Physically - It seems that people often don’t realize how much the way a woman moves plays into how alluring she is. Take something like belly dancing or poledancing classes; not even for the actual act of dancing, but rather so that you can become comfortable with somewhat curving, sensual motion. After that, just give all of your normal movements a tint of that sensuality. The way a woman walks, the way a woman moves her arms, even the sensuality present in the way a woman moves her facial muscles when she speaks - all of these things can be insanely alluring on a very subtle level.
Stylistically - incorporate into your clothing the “lingerie theory” - i.e. it’s not about what you show, but rather about what you don’t show. Find clothes that you feel really emphasize places on your body without showing them. Things like tops that focus on the shape of the bust but don’t have much cleavage, or dresses that fit the form of the hips and legs but are long enough to keep a man from feeling like he can see what he wants, or even things like a bellybutton ring or a top that lifts just a little higher than your pants that will draw his attention to an area that he wants to see, but then is covered very well by clothing… all these things have a certain allure to them. Basically, if it seems like its so classy that you’re not trying to be sexy, but it clearly can be sexy if you think about it that way, it will have an allure to it.
Also, a very certain type of jealousy can be alluring and actually good for a relationship. I’m not talking about making him think you are or could cheat on him; that could easily have the opposite effect that you want. He just needs to see that other guys are noticing you. Don’t show him this through anything you seem like you could be intentionally doing - i.e. don’t flirt with other guys or tell him about all the guys that hit on you. Rather, once you have that alluring walk and dress down well, go out with him to places where you can be noticed by other men. Pretend that you don’t even see these other men checking you out, but he will definitely notice. Focus on him as though no other man matters to you, and when he sees that you could have plenty of men but you have a heart for nobody but him, then he will be pulled all the more deeply into your charm.
On top of all that, the only advice I have is the very general “be exciting and new”. This applies to all catagories of life. Go out with him to do new social things. Try new food at home and eat out at new places. Encourage him to try new things with you. Be confident and seem excited about finding new areas of life. And, of course, trying new things in bed is always good.
Those are the types of things that I have found alluring about women. I don’t know if your husband is similar, but I hope it helps.