A face mask should fit snugly against your face. To prevent slipping over time, tie your upper ties tight and at the crown of your head — this is especially important if you have thin or fine hair. For those with thicker hair, the straps should stay firmly in place. Wearing a hat will also help create some friction to keep the straps from slipping. If you wear your hair in a ponytail or bun, tie the upper straps above it (see photo). Still having slippage? Try using bobby pins or clips.