I can't say firsthand, as when I'm cooking that's all I do. But those mesh covers that look like tennis rackets with very fine stringing are said to prevent---or at least minimize---boilovers.

If you must leave the stove, then don't cover the pots. That won't totally eliminate boil-overs, but it will keep them to a bare minimum. So, too, will using a larger pot, so there's plenty of room for expansion. Ideal would be to have a pot that's no more than half full.

Best advice is to use a larger pot--one that has plenty of extra room.

I find that for cooking rice, using an enamelled cast iron pan seems to do a good job--don't whether it's the shape (I have the Lodge apple) or the fact that the lid is so heavy, but I never have boil-overs when I cook my rice in it.

Thanks both of you. You're right of course--I should have realized that. I always reach for the smallest pot simply because it's easier to use and easier to wash. I'll grab the big pan next time. I have a splatter screen. I'll try it too.