Try learning and sticking to one opening, if its a lesser used one even better. I only use the english opening as white, as it makes it fairly obvious what black will play, and if i'm black I always use the modern, regardless of what white plays. Keeps 'em guessing as I can easily modify to fit.
Also means that all those hours they've spent learning the most popular responses to d4 or e4 go to waste, and you have an immediate advantage. If you can get off to a good start, hold out in the mid game, the end game should usually solve itself.
I'm punching above my weight because of this imo, have beaten far better players than myself just because they're used to facing sicilians and the like.
This will probably only work to a point, as I'm starting to find players closer to 2000 know the lesser used openings at least as well as me, and their mid game ability makes up for any advantage i manage to gain in the beginning.
However, until you start playing people over 1800, I think the above should work for you too.
my rating is around 1400 +/-. what can i do to increase my rating to 1700-1800.
what kind of traning do i need to do.