I use Sticky Wash away stabilizer on the back. Sticky so that you don't have to spray on anything. On top I put wash away thin stabilizer to prevent stitches sinking. About needle, I use embroidery needle. The reason is the embroidery needle has bigger hole and the hole top and bottom edge are rounder so it won't break the thread easily or thred the thread easily.

I need help on this, too. When I tried to do a t-shirt, it puckered the fabric and did weird things. What are all the tricks on using t-shirt material?

Like ssarner I use the sticky back wash away and wss on top. I also do a basting stitch just to be sure the fabric stays put I know it's over kill but I hate puckering. I use a 75/11 needle. There is also a great video at
http://www.emblibrary.com/EL/elprojects/holder.aspx?page=videos
I also found the applique video to be very helpful for hooping tee shirts and baby items.

I just made quite a few for my son...used a medium tear-away, one layer and an embroidery needle (90/14 I think) and they always come out great.

I use an iron on stabalizer 4 the t shirts & sometimes add tear away also. It depends on the type of design *

I have used No Show "PolyMesh" Cut Away Stabilizer and WWS topping or dilute some WSS scraps on water spray the shirt, let it dry and there is no need for a topping.

Here is one of many T's I made sometime ago using the WWS scraps solution.

I do lots of tees. Always wash first, then steam the stabilizer to preshrink it too! Use a cut away on back & WSS on front. I have been basting things in the hoop a lot lately to save having to hoop them as well as get them exactly where I want them! If the first one doesn't work right, also add an iron on stabilizer before you start to hoop it (or baste it.)