Don't worry about studying specific openings as it is very unlikely you are just losing because of that. Limit your opening study to the principles, playing over master level games in the openings you like to use and maybe learning a few moves in those openings -- though most of that will come from experience.
Idealy, play longer time control games; blitz doesn't give you much of a chance to really learn very much. Do tactical exercises. Learn basic endgames. At lower rating levels, almost all games are going to be decided on tactical shots, either falling to them or missing them.
ok this is probably a pretly lame question, but the thing is I dont have the time that i would like to dedicate to chess. I started playing about two years back, got hooked to it quickly and have been playing regularly (more or less) ever since. What I realised recently is that I am a casual player and if I really want to better my game I have to put in some amount of work / time. My current rating is around 1200 I think (fluctuates between 700 - 1100 for blitz). So whats the easiest way to grow (not in terms of ratings but in terms of general understanding and gameplay)? are there specific openings I should try to master? I have been a 1.e4 player for a while, recently switched to d4 and started experimenting with QGD. What are the openings i really cant afford to not know? Or are there any exercises etc I can do? All responses appreciated.