This is an individual preference whether or not to stretch your fabric while you are stitching. I stretch my fabric because I don’t trust my tension when I stitch.
When I first taught myself to embroider, I used a wooden hoop with a screw at the top. It’s a good method if you don’t leave your hoop in the same place too long. Take it out of the hoop when you put your project away for the evening.
I started working for Kooler Design Studio and saw the stitchers using stretcher bars. Now I’m doing the same. The stretcher bars are easy to hold, don’t need to be removed when you’re not working on the piece, and allow more freedom to move around on the fabric. The entire piece is all stretched at one time. You need to have a bit more fabric on the edges to accommodate the stretcher bars, but I really like to stitch with them.
Of course, some stitchers don’t use anything at all to keep tension on their fabric. The choice is yours.
I must say your own website is actually outstanding! I will undoubtedly arrive again once again!