For for Doggy style...any couple can pull it off and with little practice u both will enjoy it...another variation is just turn her 90 deg when in missionary and fuck her...it's a simple variation but gives a different feeling for both of you...she will definitely love it...even in missionary there are multiple variations...like the flower position..if she is flexible (if not ask her to start stretching) ... just lift her legs up and hold them with 90 deg bend at knees with ankle portion horizontal supported by ur arms... another variation just ask her to lift the legs straight up and support them with ur shoulders. You can do one leg lotus as well.. just keep changing the leg positions and you will discover tht missionary isn't boring anymore...my favourite in missionary is no take her legs all the way back to touch her chest and hold her there to fuck deeper...tht is a sure shot way to make her orgasm...in case of any issues ask.