Locate the area of the glove in which the leather laces have become loose. This is not a cause for alarm, as most glove laces will loosen over time and through continual use. While the glove has laces running in many directions, most likely the laces will only need tightening in a few locations.
Untie the knot on the lace at the back of the glove's pocket. This thin lace runs around your pocket, thereby strengthening it. When the knot is untied, pull either end as hard as you can and retie the lace with a reef knot or double knot. Sometimes, you won't be able to pull the lace at all. This is a good sign, as it means the lace is secure and the knot is simply loose.
Untie the knot in the lace located just over your thumb. This lace is looped through the glove to form a holder for your thumb and commonly needs tightening. Pull the lace through the glove to create the size of the thumb loop you find most comfortable, and tie it tightly with a reef knot or double knot.
Examine the knots along the thumb and on the backside of the baby finger of the glove. These laces criss-cross across the top of the glove's fingers and ensure a tight web in the glove. If these knots are loose, untie each of them, pull the lace as tight as possible and retie them in a double knot or reef knot.
Examine your glove after every period of lengthy use to determine if the lace knots are still tight and sturdy. If not, untie them and tighten them again.