Cloth modelling "Without using garment maker"

Hello guys, I need help regarding modelling general clothings without using garment maker. I searched many forums and videos for cloth modelling but all of them use garment maker.

I can model by using a plan and modifying it to make it look like cloth but the problem arises in unwraping where the final output comes with stretches near the seams. Is there any way to solve this problem?? you can suggest me some tutorials too...

Thanks in advance