As long as your loose toilet doesn't have a broken flange, you can usually tighten the bolts with a crescent wrench to resolve the problem, but don't overdo it or the porcelain may break. See how the pros do it this free video on toilet repair tips.
I'm Terry with Towers Murray Plumbing, here to show you how to tighten a loose toilet. Now to tighten a loose toilet, the first thing you want to do is start down here. Now some toilets are going to have a small cap that hides the bolt. Each one is a little different. Normally, they'll just snap off and this is what holds the toilet in place. Now, hopefully your flange hasn't broke. If you've got a broken flange you may have a bigger issue. At this point you'll need a small crescent wrench or a pair of pliers. You can go ahead and snug that up, repeat the same thing on the other side. Once you have got both sides retightened you'll want to make sure your bowl doesn't wiggle back and forth. You've got to be careful and don't over tighten those bolts. You don't want to break your porcelain. Then the next thing you'll want to do is flush the toilet three or four times, make sure you don't have any leaks. If you've got a leak, you're going to need to pull that toilet up, replace the wax down below and then reinstall that toilet. And again, I'm Terry with Towers Murray Plumbing, and we've shown you how to tighten a loose toilet.