Hello,
A very good question.
When your dentures are causing discomfort, the natural tendency is to adjust them yourself, but this rarely works out for the better, and usually can cause more complicated problems later on. If any adjustments are required, I advise you to return to the dental practitioner who made your dentures.
If you are returning too many times, I would suggest you ask the dental practitioner why, and what is wrong with the dentures.
Sometimes, too many adjustment will ruin the fit of dentures, resulting in a much needed reline or rebasing.
I hope this helps.