1- The smaller the mask, the better off the chances of creating a good seal.
The less mask contour, the less chances there will be a mismatch between the mask and your facial features at any area, hence the less chances of CPAP mask leaks. So Nasal mask is better than Full Face mask and Full Face mask is better than Total Face mask.
2- Facial oil build up will break the seal during the night. Hence washing out your face before sleep will remove all daily facial oil build up and will increase your chances in preventing Mask Leaks.
3- Masks without a forehead arm are notorious for mask leaks because the mask needs to have a firm grip at upper and lower borders (through their straps) in order to achieve a good seal. Yet Masks without a forehead arm, their straps are coming off at middle and lower level of the mask instead of coming off at upper and lower borders of the mask. (Pictures below)
4- Mask Straps are deceptive. As they age, they lose their elasticity hence their grip on the mask. Every few weeks make sure you adjust the mask straps to compensate for losing elasticity. Mask straps should not stay at same position throughout the life span of the mask. Follow mask straps recommendation for replacement and even replace them more often than the mask, otherwise as they lose elasticity, they can cause mask leaks or worse yet become like a hard rope when you tie them extra which causes a head bruises.
5- Nasal bridge trauma as well as other mask facial trauma will prevent you from tightening the mask straps tight enough. Make sure you get the best mask possible for your facial features. There are web sites out there that allow you to buy the CPAP Mask with insurance for return. That will give you the opportunity to try different masks with least amount of cost. Invest to choose the right mask.
6- Trying out a mask at the doctor office or the medical supply outlet is totally different than sleeping with the mask. As you sleep with the mask, facial oil build up is a factor that cannot be avoided and it will tend to be a major factor in creating a mask leak.
7- Any tactics that can allow you to lower the CPAP pressure even by 1-2 points (by doctor approval) will increase your chances in preventing mask leaks. Examples: high pillow, stopping smoking, Medically proven breathing exercises, weight loss, among others can help you to lower your CPAP pressure by few points which will significantly increase your chances in preventing CPAP Mask leaks.
8- Gaining or losing weight even by a few pounds can mess up the previously well balanced good seal.
Masks with Forehead arm. Straps are coming off upper and lower borders of the mask.
Masks without a forehead arm, straps are coming off the middle and lower border of the mask leaving upper part of the mask without a grip.