Ties: a piece of material that ties behind your head or behind your ears and can allow for adjustments.
Loops: these can keep the mask more securely in place but are not adjustable. If ear loops are preferred, but you've experienced discomfort, look for a product called ear savers, which connects the loops at the back of the head and takes the pressure off the back of the ears.
Elastic Cord Adjusters: For kids or those who have smaller head widths, elastic cord adjusters can be a lifesaver. They typically come in packs of 100 that sell for on average $10-$12.