I have made several. I did cut out my T before putting the stabilizer on but that is because I am cheap and didn't want to waste it. I do agree the T's behave better if you stabilize first then cut but many have cut first and stabilized after.
I cut 12 1/2" blocks from my T's and cut the stabilizer the same size and also used scraps of stabilizer. I think T-shirt quilts are easy but I may be in the minority. Before I got my longarm I would tie them but now I quilt them on the LA with no issues.
There are many ways to set them. Here are two that I have posted before:
This one is longarmed
Double sided T-Shirt quilt
This one is tied. I have made several of this style:
Harley T-shirt quilt
Edited to add, unlike PTquilts, I have never had an issue with my stabilizer having to be re-ironed but I do know if the T's have been washed with fabric softner or a dryer sheet that can impair the adhering of the fusible stabilizer. I have used both JoAnn store brand of fusible interface the lightest weight they had and Pellon name brand. I do like the Pellon better but the JoAnn stuff worked fine too.