what type of carrier do you use?

This is the one I have and I HATE it. It makes my back and shoulders hurt and it seems uncomfortable for my son. (He's 3 months old and weighs 16lbs)

http://www.target.com/Evenflo-Snugli-Comfort-Vent-Carrier/dp/B0010WBPNI/sr=1-3/qid=1224514485/ref=sr_1_3/601-8744039-2964905?ie=UTF8&index=target&field-original-keywords=snuggli&rh=k%3Asnugli&page=1

Any suggestions on a more comfortable carrier? I was thinking of getting maybe a wrap or ring sling?

If you have a wrap:

did you buy it or make it?

If you made it, do you have directions? My husband's granny is an excellent seamstress, so I'm sure she can help me.

Sorry so many questions in one! lol