Tips for orgasm?

Hi ladies! I'm hoping that this is a common problem and not too much TMI, but I seem to only be able to orgasm when I'm by myself. Also, when nothing has entered me and I'm just rubbing the top of my vaginal hood. The orgasms I have then are usually just a warm throbbing sensation that almost makes me hold my breath. Sex with my husband is great, but I just can't seem to get the same feelings when he's inside me. Any tips would be very much appreciated!