It's important to keep a regular schedule for your meds. Take them at the same time each day. They work better if you keep a constant level of medicine in your body. Don't skip a dose, because it can trigger a flare-up.
Keep in mind that some medicines, like methotrexate, can take weeks or even months to completely kick in. Try to be patient and give your meds a chance to work.
If you get an upset stomach or other side effects, call your doctor. There are often things you can do to feel better.