While there are many benefits of group practice - access to role models, tips, feedback, help, assistance, motivation, etc - and mentored practice, you will need a lot of repetitions by yourself.
After 1) finding what to work on and 2) identifying a path that may work for you, especially 3) the repetitions (and variations) will mainly be your thing to work on.
So how to best do it?
Find space, a space, facility
Exception to the rule: if you're space constrained make a challenge out of it - what can be done, how can that even be an advantage. See Futsol creating some great dribblers.)
Indoors, how about using a soft ball that's quiet and doesn't destroy anything?
How about a playground?
Forest? Trees? Rocks?
Tools
Balls are great, they make you move / dynamic
With nothing else around, you can juggle with one or both hands
With a wall, you're starting to get some "interaction"
- A good one may be surprisingly hard to find - factory, underpass, tennis facility?
- A bad wall can also help, e.g. to train reflexes and flexibility
Anything with a lever adds a challenge, e.g. racquets or sticks
Reversely, removing that lever can help to make things easier (see /progression)
Otherwise, there are a lot of day-to-day tools and activities (see /label/day-to-day)
Getting on wheels opens other possibilities and adds balance challenges, e.g. skateboard, skates, bike, unicycle, etc.
Like with other practice, do X sets of Y
In the spirit of Backhands Optional, practice both left and right
Prioritize the weak side to catch up (more on that later)
Strive for ideal, smooth movements
Consciously add in variations, e.g. to close in on the ideal and prep for future flexibility
Look for your "edges" and breakthroughs, and don't overdo it.
Find some way to assess yourself, e.g. how does it feel, the result of what you're doing, mirror(ing) surface, video, or ask someone to watch and provide feedback (see "How to practice").
Ideally, you've set some goals before and are open to iterate on them based on your learnings and progress.
For practicing with others, find some thoughts here...