I have nightmares every night, sometimes worse than other. Some turn in to full blown flashbacks when I wake. Some turn into night terrors when I partially wake.

Nothing makes the actual DREAMS better for me, but developing the habit of immediately reaching for my stuffed bear, and recognizing what it feels like, and snuggling it close when I wake up helps. I also immediately look around the room and recognize my big red numbered alarm clock. I can reach up and feel the headboard of my bed, and tactilely recognize it. I listen for the fan I always leave on, and recognize the whir. I use all these to ground myself in the present, knowing where I am and that I am in a safe place (well as safe as anywhere I will find). All of these help me to come down easier after a nightmare.

I hope it helps, sorry I don't have any suggestions for controlling or effecting the actual dreams.