The chin strap never worked for me and I tried several different ones.
Some things I have done that have allowed me not to have to use the CPAP mask:
1. Elevate my head on the bed with 2 medium thick pillows or 1 fat 5 1/2" thick pillow. You can put books under the head of the bed to elevate it. I have one of those sleep number beds so can easily elevate the head. I try to keep it as high as possible w/o being in an awkward position and hurting my back.
2. Put pillow under my knees to keep my lower back from hurting from sleeping w/ head elevated.
3. I'm a back sleeper and uncomfortable on my sides or stomach but try sometimes to sleep on my sides which is definitely recommended for apnea
4. I have always been a mouth breather at night since childhood. Was desperate to find something that would keep my mouth closed and tried several different tapes that pulled skin off my face.

On Amazon I found 3M Micropore S. The 1" high is 2770-1 and the 2" high is 2770-2. Both are 5.5 yds long. Last time I ordered, they only sold by the box w/ 12 rolls of the 1" size and 6 of the 2" size. It does not pull the skin off around my mouth and sometimes I even use the 1" size on other parts of my face to "iron" out little wrinkles while I sleep.
I use the 2" high for my mouth. After I apply I blow out to see if there are any areas that are loose - if so, I put some 1" tape on those areas.
I use Snore Lab app on my iphone every night and get a snore score every morning. The score represents the amount of time I spent snoring after I have deleted all noises that werent snoring - the app shows me EVERY sound EVERY SECOND I am sleeping including my husband getting up and showering.
It is easy to listen to and delete sounds that obviously are not snoring. I've done it long enough, that I can delete nonsnoring events just by looking at the results. When you snore, it looks very different than if you make a noise turning over, or someone rings the doorbell, or any other noise that occurs during the night.
Often my scores are between 0 and 3 which are low and GREAT so I dont have to use the CPAP. Snore Lab says score of 25 is Ok but I dont think so.
The app has helped me notice that often the interval between snores is very regular, like 4 seconds between each snore. I am trying to find a technician type who analyzes sleep studies to see if that indicates normal snoring or obstructive apnea snoring. I dont yet delete that regular interval snoring from the daily results and still get very low result w/ mouth taped.

PS - A dentist who specialized in oral devices made one for me and I used it for a long time, but I kept on getting cuts inside my mouth from the metal pieces on it, had to put special band on it to try to keep mouth from opening which didnt work that well and results were not as good as w/ the tape. Once the dentist got paid for the appliance, he wasnt that helpful. Also worried that if I kept on adjusting it to make it pull my lower jaw further forward, I would get TMJ. Hope this is helpful and clear. I just joined so not sure if I can give you my email address for questions - let me know if you know if I can. I will look for a Reply just in case you do reply.