I used the same fabrics as my support tank to make a sports bra (cotton lycra and stretch mesh from Glitter and Dance).
The pattern is one that I made by cutting up a RTW bra.
The side seams are enclosed between the inner and outer layers. the edges are bound using my binders and coverstitch machine. The underbust elastic was attached with an overlocker, turned up and zig-zagged in place.