Hi there! I dont know if my answer is helpful, but I managed to raise my rating from around 700/800 to 1400 now within almost one year. All I did was playing a lot (5000 blitz games, i think around a bit less than 1hr/day) and watching many chess videos on youtube, mainly from 'kingscrusher'.
Suggestions needed in improving my game

Tactics, basic endgames, and opening principles. Especially tactics and endgames since you'll learn both technique and coordination and the geometric relationships between the board and pieces. For example after a certain tactic if you see a connection between d8 and e1 via Qh4+ or Qa5+ then you could win a hanging bishop. Then you have checkmating problems that teach you the mechanics of those particular operations, such as destroying cover, utilizing their own pieces to cut them off (smothered mate for example) and such.Â

Escobar, so 1200 can be a realistic target.. that's some hope.. In particular I notice when ever I try Lopez or queens gambit I end up weakening either light or dark square and I lose the center.. but with fincheto (not sure how it is spelled). I have some successes but 800+ players I end up constrained in terms of space... should I mug up all the variations... or is there a in principle guide line to be followed..

... should I mug up all the variations... or is there a in principle guide line to be followed..
No. Do what TheGreatOogieBoogie stated. You'll get more out of tactics and endgames and opening principles than you will out studying tons of opening lines. Most people at lower rating levels will be out of book by move 4 or 5 anyway.
I haven't looked at your games but I will guarantee that you are missing tactics and probably leaving pieces en prise (or missing hanging pieces of your opponents).
Also, playing slower time controls and taking your time on your moves should help too. It's really easy to miss stuff in fast time controls.

Learn the basic, keep learning until you master it. Â Once you know the basics, then other things come. Â What is basic? Â Knowing what you are doing on the chess board i.e. Â When making a move, is it safe. Â Look at the whole board. double check your every move. Â Ask yourself question why he made that move. Â Dont just be concentrating on your move only, see what your opponent is up to & etc. Â Trying doing this first. Â Also learn tactic & end game. Â You can go to chess.tempo for unlimited tactics. Â Remember basic is the BASE & it is very important.

I watched a few videos on openings, but never really studied them. I copied a small repertoire of openings which I came across and worked on them via 'trial and error' in online chess. Many positions will occur severall times and if you do a mistake, next time you avoid it or try sometimes a different move in the hope, that it turns out better than the one before.
If some day I manage somehow to achieve a.. lets say 1700 rating.. I should probably start to learn some theory, but before i think the learning curve rises faster with practise and not with theory.
Practise also vastly helps to avoid blunders, which are quite common for ratings 1200 and under.

Hi currently I am around 700 odd , when ever I think I have learned few things and start a fresh my score reaches 800 odd. but gradually I am back to 700😢. can any one suggest where I could be going wrong... And can i aim to cross 1200 in next 6 months ? I started couple of weeks ago... any suggestions ..
1. Tactics
2. Basic endgames
3. Play people better than you
Here is wht you need to know about Openings:
Find 2 openings you like to play and learn the ideas/principles behind those openings.
1. Control the center
2. Develop toward the center
3. Castle
4. Connect your Rooks
read my system for aron nimzowitch then start studying opening theory via some books not this site as they are un organized or explained  can recommend one , also watching chessgames on kings crucher is important as you learn correct move sequence and annalysis as you will get some grandmaster tactics .
to improve generaly , you need practice more theory like am doing  now (openings go on to like 15 moves and onward with many variations ) and improve your tactical vision ( look at the chess website channel ) .

read my system for aron nimzowitch then start studying opening theory via some books not this site as they are un organized or explained  can recommend one , also watching chessgames on kings crucher is important as you learn correct move sequence and annalysis as you will get some grandmaster tactics .
to improve generaly , you need practice more theory like am doing  now (openings go on to like 15 moves and onward with many variations ) and improve your tactical vision ( look at the chess website channel ) .
At his level, the last thing he needs to be studying is openings, esepcially theory. And there is absolutely no reason to memorize 15 moves deep.
well i-am-second , by my experimentation i must tell that studying deep theory this ealy eliminates opening blunders and  confusion later on in the game and you wont improve if you play weak openings and in chesss if you play an accurate oponent a mishap or deviation from theory destroys you .

well i-am-second , by my experimentation i must tell that studying deep theory this ealy eliminates opening blunders and  confusion later on in the game and you wont improve if you play weak openings and in chesss if you play an accurate oponent a mishap or deviation from theory destroys you .
How many people at your level know openings 15 moves deep? And what do you do if they play a "non book" move? Studying deep opening theory doesnt eliminate blunders, tactics do that. After 15 moves of opening book, how do you formulate a middle game plan?
If you enjoy studying openings then carry on, but its going to slow your develoipment.
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ok but i must remind you fischer took great care in studying openings , not that i disagree really but what i ment is perfecting your openings allows you to improve tactically as yo can setup a good position to start off from instead of messing it up from move 4 at best wishes

ok lets put an end to the argument. Â First learn the basic. Â Nothing will help if you dont know or do the basic. Â 100 good moves is nullified by 1 bad move!
Learn tactic & end game play. Â What do i mean by tactic? Â Learn how to attack & defend using tactic. Â Recognise the patern. Â It is important. Â As for opening, if you are just using book moves without understanding it, it is of no use. Â For me, opening can be learnt after you have done your BASICS. Â Remember, basic is the BASE & FOUNDATION! Â A building is build on STRONG BASE/FOUNDATION. Â Otherwise, it might collapse. Â So built a strong base by mastering the BASIC. Â Then learn tactic & end game. Â
To learn an opening, understand it. Â Why a move was done. Â What are the important points of that opening. Â No need to go for long lines. Â Learn easy lines first & then learn from experience. Â Take your game & analysize it with someone. Â Oh yeah, if you really want to improve, stop blitz & bullet games. Â Concentrate on slow live game. Â Maybe try 15 min then extend the time to 45/45 or 90/30. Â You can play correspondence but refrain from using the board. Â Use your imagination. Â It might be hard at first but as you keep doing it, it will be come easier.
Finally, materialistic16, yes Fischer took great care in studying opening but dont forget that he begin by learning & mastering the basic first. Â He built a foundation. Â Remember, he started playing when he was 4 years old if i am not wrong. Â Only later he concentrated on the opening. Â That is why learning opening is of nearly no use for beginers. Â Â

ok but i must remind you fischer took great care in studying openings , not that i disagree really but what i ment is perfecting your openings allows you to improve tactically as yo can setup a good position to start off from instead of messing it up from move 4 at best wishes
I get what youre saying, but starting with openings is like putting the roof on the house, and not laying the foundation. All positions arise form endgames.

I think you guys are missing the best advice: stop losing pieces for no good reason - I
LOL.....that is part of the BASICÂ

Hi currently I am around 700 odd , when ever I think I have learned few things and start a fresh my score reaches 800 odd. but gradually I am back to 700😢. can any one suggest where I could be going wrong... And can i aim to cross 1200 in next 6 months ? I started couple of weeks ago... any suggestions ..
Youre not going to improve if all you play is 5 min games.
Hi currently I am around 700 odd , when ever I think I have learned few things and start a fresh my score reaches 800 odd. but gradually I am back to 700😢. can any one suggest where I could be going wrong... And can i aim to cross 1200 in next 6 months ? I started couple of weeks ago... any suggestions ..