First of all, you need to have leather gloves which completely fit your hands as too much tight or loose gloves actually damage their surface.
For cleaning your gloves and keeping them protected, you should use a damp cloth and wipe the gloves which will remove dust and any other particles.
Use soaps which are made specifically for cleaning the leather. Try to repeat this process whenever you feel that your gloves are getting dirty.
Using a leather conditioner is the best way to keep your gloves neat and clean. Leather conditioner usually maintains the softness and shine of leather gloves without damaging the surface.
When you are not using the gloves, try to place them in a cool place. Try to keep gloves away from direct sunlight as it usually damages the surface of the leather.
Also make sure that you have kept the leather glove away from moisture. But if you find your gloves wet then immediately try to dry them as delay can damage the shine.
If you feel that leather is losing its shine and they are getting rough and dry, then apply gel shaving cream with lanolin on gloves and rub it gently.
Try to avoid giving your gloves to other people who have bigger hands than yours. It can damage the gloves.