Get a wire comb for one (it cuts down static, which will help the fibers from catching and kinking). Make sure you are throughout the day having people check it to make sure no huge knots are forming at the base of your neck. Try not to bother the hair as much as possible. Leave in moisturizer for wigs tames them a bit as well. Lots of tips one could give, but in the end there isn't anything to be done about long wigs tangling over time. You just have to make sure that EVERY time you wear it you have some time to fix it afterwards. Getting a heat resistant wig is also a plus since you can use a straightener on a low setting to fix any hairs that happened to curl up or get caught and broken during the day. Don't be afraid to trim individual hairs that are just ruined to save the bulk of the wig.