You could purchase an exposure meter for darkroom printing. I believe RH designs makes one.

Keep in mind that every time you make a change, and tweak something in your print, you learn something new, and that improves your skill as a printer.
The paper in the darkroom trash can are valuable lessons learned.

And, if you use the same film and developer every time, you will know a lot more what to expect come printing time, which saves a lot of guesswork and paper waste.