Question: When a wife is more experienced than her husband and wants to get a bit more creative in the bedroom, how can she approach this with her husband in a way where he doesn't end up thinking of her previous experience?
Answer: When you ask to be a bit more creative, I assume you're looking for increased pleasure and intimacy. If you're looking for those things, I would consider emotional intimacy as a route to get what you are looking for. It kind of sounds like you are self-conscious about your previous experiences, so you may be acting more inexperienced/shy in the bedroom. If this is the case, then you are in fact obstructing the true intimacy you can feel together. I would consider truly accepting yourself and asking yourself if you have any reason to feel self-conscious.
Has he made an issue of your "previous experience" before? If he does have an issue with it, then this is likely rooted in him feeling very sexually insecure.
If he has accepted you for who you are, then this is your insecurity that is getting in the way. What is underlying your feeling self-conscious? Are you regretful? Do you need to forgive yourself and accept yourself? It sounds like you'd like to be more active or spontaneous. I would encourage you to be more true to yourself in all the ways and accepting yourself for your past! If you would like to change positions, go for it! If you would like to do something new that you haven't done, touch him in a way you haven't done, kiss him in a way you haven't done, then initiate it. You could tell him that you were reading or looking in to some things, and thought you'd like to try X. You could say "hey I don't think we've ever done Y, let's try that sometime," or "I'd love to try Y. What do you think? Interested?" Most men will welcome more eroticism and more spontaneity. By you being more true to yourself about what you want, you will feel that you are opening up and being more intimate with him. This will, in turn, enhance your pleasure and sexual connection.