A number of years ago when I was married, my wife and I used to do DPs using a dildo and my cock in her pussy. She loved it and it felt good to me. Evan after three children she was fairly tight, and so we used a medium size dildo. Usually we would start off fucking normally, and then she would ask if we could have Tom (the name she called it) join us. I would fuck her for a while with the dildo, and when she got really excited, I would slowly add my cock to her pussy. The filling sensation of the DP usually made her cum, something she never did when it was just my cock in her pussy.
She did not like anal so we never tried that kind of DP.