Beginners should work on getting the ball from their foot to hand consistently. Right foot catch, left foot catch. Once they are able to do that try adding one juggle each time until that can be done consistently. It may take a little bit of time but every player can do this.
Intermediate/Advanced players should set daily targets to try and reach and try mixing it up using different body parts and variations. A few ideas in this video for you.
A few more ways to work on first touch and control. Can be done with any wall / rebounder etc. Included are some examples of using different parts of the body to control the ball, foot, chest, knee.