There is no foolproof way to guarantee a quick rating rise - for it depends on competitive results. All we can do is help you improve your game, and hopefully the competitive results will follow.
There are a few ways to improve your game at that level. Some have already been stated, such as lengthening your time control and playing more often.
Those should work fine, but I also recommend solving puzzles on the Tactics Trainer or from a book. Even just a few a day will help sharpen your tactical vision and, consequently, lead to you seeing more on the same chessboard.
And one more thing: Analyze your long games after you're done with them and see if you can find recurring mistakes. If you can, eliminate them!
It will be near impossible to get your rating up quickly later when you're around 1800+, unless you're a prodigy, but at your level, the best thing to do is do tactics, play a good amount of games, and perhaps study a few beginner books.