I use compression straps or 550 cord (paracord). You can get stuff super tight, and if you need it, you have extra cord.
I'm also a fan of the garbage bag waterproofing of sleeping bags. I stuff it in the garbage bag, then the stuff sack.

Tent and sleeping pad are in front waterproof panniers with food and clothing. If it rains, I take the tarp under the sleeping bag and use it as shelter or a rain cover for rear rack.
EDIT: HA! just noticed that I'm using bungees in this pic! But I don't anymore.
Seriously.