In this page you will find some quite useful chords mainly used for Acoustic Guitar. This chords can be exchanged with the basic chord.
Let me explain to you how does it works.
If you have a progression of basic chords like E major and A major, you can change them with an E major 7 and Aadd9 to add a bit more color. All this chords works quite good on pop/folk songs but feel free to experiment and come up with your own solutions.
Enjoy!!