At this time of year there are dozens of T-shirts in the shops, all looking the same, all at various prices from the very cheap to quite ridiculous prices.
I am guilty of buying new ones most years, but wait, why should I keep spending money just to look the same as everybody else? Why should I put up with the store dictating to me what the neckline should be like, what length the sleeves should be, how long in the body it should be? And thats only the start of it, try buying a nicely patterned one..... You see the problem?
Many people ask me about sewing with stretch fabrics, and are daunted by it. But don't be, with a few simple rules you can be sewing your own "designer" tops quicker than you can go to the shops to buy one.
Your first attempt at sewing stretch fabrics might not turn out exactly as you would like, which is why I recommend you making a Toile or test garment first. For this find some cheap jersey fabric or an extra large men's t-shirt to practice on.