I have no source for pelvic massage. I would just warm up the area with a hot rice sock and then massage and press into any tight muscles. The shower is a good time to do this too.
I can last as long as I want, but I can't last as long as I want the way I want to. When I start reaching PONR all I have to do is switch positions and the sensation will lessen. When I do this it usually gives me 5-10 more minutes. I can do that all night.
I can't control PONR the way I want to, which is my next goal. Right now I am very good at keeping PONR from happening, thanks to edging. Sex is fun and feels good, and I can go 15-20 minutes most days before things start feeling really good just by staying relaxed. Normally, I can use breathing to keep going for a while at a higher level of sensation (5 minutes). Once PONR comes into play and breathing isn't enough, I either let it happen or switch positions to last longer.
Again, switching positions just to delay PONR isn't ideal. I don't usually need to do this, but sometimes I will if I can't control myself using other techniques. I really want to reach PONR and hold it there. I work on it every time I have sex.