Accepting is receiving something, as in accepting a gift, or accepting a job. Even accepting someone else’s judgment, which can be construed as agreement, is still receiving their opinion, and making it your own.
Excepting is excluding something, as in the product has a satisfaction guarantee, with the following exceptions. It is a rejection of the guarantee in certain circumstances. If you invite everyone in your class to the party except John and Susan, you have excluded them, or rejected their presence at your party.
Remember the difference this way: Except, Exception, Excepting all contain the letters “ex”. When you have an ex-spouse, or ex-significant other, you have rejected their presence from your life.
Accept gifts presented to you, except those from really creepy strangers you don’t want to include in your life.