If you are riding remote areas and want to be sure you'll get home, carry the same stuff you would if you had tubed tires. Extra tube or two, CO2 inflator and cartridges, mini pump, patches, tire boot as Elvo says.. Also carry some kind of plugging tool. I've used the bacon strips, but recently tried a Dynaplug tool on a 4 day 412 mile ride across NYS and the Dynaplug was worth it's cost...plugged a cut that was almost 1/4 inch in just a few seconds and rode on.
PUtting a tube in is a bit messy but not a huge deal...dump the excess sealant first. Had to do this on a solo remote-ish ride where I pinch flatted on a pretty rugged forest road a few weeks ago - sliced the tire right near the bead and sealant wasn't working.
Keep your sealant fresh. It's worth the cost. Every season at the very least, and top it up after flats. Change it every 2-3 months to be more certain it will work.