1) Study chess books?

2) Analyze games?

3) Just play a lot of them?

Personally I have tried reading books: I've managed to finish one, some others I just stopped half way through because I got bored!

Analyze own games or famous ones? I don't think I have enough experience to do that. I would just go over quickly over my own games so it's not really analyzing.

Not to forget that, for 1 & 2 both takes a lot of time which I don't really have nowadays :(

I also hope to improve my opening repertoire one day. I just know some theory + endgame

I have no special openings, I have never studied any games, I just play chess!

But it's good to explore other tactics, I am just too lazy or too busy to do it!

I am not too good with openings, I just apply the basics / principles. Even so, I sometimes end up a pawn down or two with no real positional advantage

I wish I could get past the 1800, never got beyond that

I do study openings but I believe that in order to avoid the trap of getting bored with the stuff one should choose an opening, study, apply all the variations on platforms such as chess.com. Only to try another opeing when you feel you have firm grasp of the opening studied. TOO MANY OPENINGS AT A TIME CAN BRING CONFUSION I, MAY BE ONE MASTERED AT A TIME IS MORE REWARDING.

1. Analyse the games played :

• Identify what went wrong, what was the best line of continuation
• Continue with the same opening until we get it right and feel confident that we have a good control of what we want to achieve and also what we want to avoid in a particular opening.
• Keeping a note book for analysis will probably help:
• Say you are trying a line Nf3- Keep all the matches where you played that variation together and make notes.
• Otherwise, we may keep on doing the same mistake again and again, I think that if we don't analyse and evaluate a move move we'll have the tendency to do the same move over and over again because remember if we did it at the first instance we rated it as natural move. So we need to break this pattern by keeping in mind what we think as natural may not be the best, so we are making this 'natural reflex' evolve by concious corrections of our behavioural pattern.
• Have a nice time studying and analysing  mates . 

See you soon

Thanks for the tips Mico. I'll compile some of my games with same opening and try analyze it a bit. I'm on holiday, so plenty of time :)