you can keep everything in your field of vision if you look straight ahead. focusing on one particular object divides your attention and screws up any rhythm you're trying to establish

what would be most beneficial to you is learning how to juggle 2 objects with one hand. if you can master that you're good to go. it helps set the correct muscle memory, meaning tight, controlled movements with your hands. no big motions. that minimizes bad tosses and and makes it easier to recover from a bad toss

and juggling is fun. i've been disciplined for juggling random office supplies at more than one job

source: self-taught ~x0 years ago, also on some lazy weekend