I've seen a lot of people mention that they use turkey basters for moving water, food and trash around. Turkey basters are pretty cumbersome and coarse, difficult to control. I use a plastic dropper for food (BBS for the fry and frozen brine for the adults):
They are widely available at hobby shops, and I'm sure that craft stores would have them as well.
I use tweezers to feed frozen blood worms to the adults.
To siphon trash off the tank bottom, I use a section of rigid airline tubing coupled to a section of flexible tubing. The rigid tubing allows me to precisely target the trash, and the flow rate of a siphon through airline tubing is just right to get the trash and avoid most of the fry. I always siphon the trash into a white bowl, and then check for fry. I transfer the fry back into the tank with the dropper shown above.