Get the bottle with the fewest parts

For school, you want a wide-mouth bottle with a straw lid that comes completely apart. That combination gets you leak-proof and a straw you can actually clean.

Most leaks come from a bad or misaligned gasket, not from a missing lock. So look for a bottle where the lid seals with a silicone ring, and test it before buying. If possible, fill it with water, toss it in a backpack, and shake it for ten seconds. That’s the honest leak test.

For the straw, the easiest to clean is a wide, straight silicone straw. The fancy valve mechanisms inside some sports caps are traps for mold. You need to be able to pull the straw out, wash the mouthpiece separately, and run a straw brush through it. If you can’t see and touch every piece, don’t buy it.

You’re not saving time with a magic self-cleaning bottle. You’re saving time by buying fewer parts and keeping it clean. That’s the whole trick.