These juggling balls work great, and their all basically the same size. They have a good weight, not to leight. All it takes is lemons and duct tape. Just simply wrap the lemons in some layers of ductape and you have the perfect juggling ball. if it feels to squishy, just add another layer of table 
e39m5
I Hope your Joking!
dead serious, not joking. Ive been using these things all day. It started without any tape but then they started to leak on me. Then the almighty duct tape fixed my problem. You see, Duct tape is like the force, it has a dark side, a light side, and it holds the universe together. And my juggling balls
e39m5
I have a better suggestion that won’t rot on you.
Buy some cheap tennis balls from any dollar store in the area, along with some popcorn kernels (the kind that go in the air popper) and some electrical tape (I know it cost me 69c at Canadian Tire, which is really inexpensive).
You cut a hole in the tennis ball, and fill it as much as possible with popcorn then tape the whole thing up really tight. They’re a little bit heavy, but you get used to them very quickly.
In a week, mine look the same as when I made them, whereas yours are going to smell REALLY bad. 
Or fill them with lead shot and they make amazing training balls to stengthen your wrists.
Can you duct tape bananas together to make juggling clubs? How about cucumbers? Maybe a big zucchini.