Here's an adaptation of a gravel vacuum I use for my 8g tank with a sand bed so I can lightly stir the sand, kicking up detritus and easily vacuum it up. The one I like best has a mini nozzle I had laying around, but any tubing can work and smaller 1/4" tubing keeps the flow rate down so I can clean more sand before I run out of water in the tank. With the clear tubing I can create a mild vacuum and put the end into my bucket before I get a mouthful of fish water lol.
6-8 ft of 1/4" tubing from Ace (.23 a foot)
2 Rubber bands from LFS
Toothpick from the kitchen (free)
A standard vac with the big nozzle would work too, but a long deli sandwich toothpick might work better.
The first pic is my favorite, the second pic is my original.