No plastic bags that are sealed please. Leather has to breathe. All kinds of problems when you seal the glove up in anything...mildew, over dryness, smell. Don't put them in anything, boxes, bags that are closed up and sealed.
And keep them in areas with level and normal temperatures, no extreme cold or heat. Watch out for humid areas too as this promotes the leather to deteriorate.
Treat your leather like skin which it is.