Keep in mind that the smaller the hearing loss the more sophisticated the hearing aid you need to get a benefit. If you have a slight hearing loss you will experience issues in the "hardest" situations for hearing aids to cope with such as conversations in noisy places or bad telephone reception.
Finally, the over the counter hearing aids come with a limited number of pre-fitted configuration (e.g., 4) and "tweak yourself" means choosing one of them. To get a hearing aid fine-tuned to your specific hearing loss you need a professional in a shop equipped and trained to use with the professional fitting software of the hearing aid