1 Pre washed:
Cotton tends to shrink after the first wash, so next time when you are buying cotton fabric ask if they have pre washed variant.
2 Starch wise:
Some cotton fabrics have a better fall if they are starched after the wash. Ask your retailer if the fabric needs to be starched after every wash.
3 Colour code:
Don’t buy very bright colours. Even though the colours are fast, they may lose lustre when dried in the sun. Also, don’t buy cottons that are mixed with fabrics like polyester, as they don’t dry the sweat percent cotton would.