For this position start by having your lover sit down, with one leg straight and the other bent at the knee. 
Lie down with your knees bent. Then have your partner sit and wiggle their legs under yours, pulling your body close. 
For this position you & your partner should face one another and kneel on the same leg, so you both have your right or left leg out. 
Start by leaning your hands against the wall and pushing your butt outward.
Lie down and have your partner kneel in front of you.

For this position start by stacking 3 or 4 firm pillows into a pile. 

Start by having your partner sit down on the bed with their legs extended.
First, find some stairs! Then kneel down so your butt is sitting back.
Start by bending at the waist and bring your hands down to your feet.
Flexibility and strength are a must for this position. Stand in-front of your lover and bend over to touch your hands to the ground. 
Caution: This position requires some extra flexibility. Please stretch before attempting.