Nothing can replace good grooming! Take a shower, if there is enough time, and don’t forget to wash your hair. Hair oil is not great for wigs and will make them smell if not washed at frequent intervals.
All synthetic wigs should be washed in cool water with a wig shampoo only. Do not use hot water or the shape of the wig will be destroyed. Use a wig conditioner as well. Get these at the wig departments in the major stores. Roll in a towel and then hang on a wire head form — not a Styrofoam one(!) to allow the air to dry it evenly. Only when it is completely dry should brushing with a steel bristled brush be done, as plastic bristles will create static electricity making the job miserable.
While on the subject don’t forget to trim hairs in the nose (UGH!) and ears. If you’re also inclined, don’t forget body hair in tell-tale places if you can get away with removing it. Trim the fingernails and apply cuticle cream if you need to.