Word for "to make something productive"

I'm looking for a verb that means "to make something productive" or "useful".

Example: If someone is wasting their time by doing something that's not productive, I might say "Spend your time [more] productively".

In the above sentence, I want to replace "spend productively" with a single word, so the new sentence would be "____ your time" where ___ is the word I'm looking for.

Is there a word (verb) that fits the above description?

Solution 1:

"Optimize" would work in your example.

To optimize your time means to make your time effective.

Make effective and make productive are synonymous.

Solution 2:

The only verbs I can come up with that answer your question in a technical sense aren't necessarily idiomatic or a perfect fit.

Some possibilities

"Optimise your time" means "Make the most of your time"

"Utilise your time" means "Make your time useful"

"Profit by your time" means "Use your time gainfully"

"Occupy your time" means "Keep busy with your time"

I could go on. I could I suppose justify the above examples by citing dictionary definitions but I'll let you do that for yourself.

More prosaically and more idiomatically I support @Weather Vane's comment. "Do something useful".

The "with your time" part is unnecessary because all activities take time.

"Stop wasting your time and do something useful!"

"Stop wasting your time and do something productive!"

The problem is there are many ways to say what you want and I'm reluctant to give a list.