Detailed guide to using water as a medium.
Ok so I mentioned using water in the domes while noogling. Why do this you may ask, simple, more even pressure, better swelling and in the long run possibly better growth. Also the warmth of the water is highly beneficial for breast growth and it keeps your girls moisturised and does much less blood blisters and less discolouration. Its a bit messy and tricky to do, but worth the effort. Doing it the old fashioned way "dry" works too obviously but I think with water its just simply better.
Setting up
You need to have gauged pump, airlocks with each dome sealed individually and the long Y-connector tubing that comes with your pump. Attach one end to the pump, the lower end of the Y should be sealed, old school audio plug is perfect size for this. Then the other upper end of the Y should have the male plug of the airlock attached. This will make sure no water enters the pump, be careful with this, water WILL break the pump.
1.
Add lube/lotion around your boobs for forming a good seal. Hold a dome with the tube shut so no water escapes. At this point the dome end of the airlock should be attached to the pump, pour in warm water, just enough so there will be enough space for your boobs to swell and some air.
2. Lean forward, place the dome so that there is seal, see that the placement is as centered as possible and no water escapes. Lean backward while holding the dome, at this point allow the tube to open so you can pump up the pressure. Pump it up while using your other hand to adjust the placement. Keep leaning backwards so no water goes inside the tubing. This is the tricky part and it takes some practice. Once you're at your preferred pressure, detach the tubing and repeat the process with the other dome.
3. Lie down on your back. At this point if you're using a rope or a belt to hodl the domes together, put that in place. Start your timer. After few minutes, check the pressure to your preferred one, this is easy as water will not enter as its on your boobs unless you know how to change gravity. Besides your boobs should be the most massive objects with their own gravity field anyway.
4. Keep checking the pressure once every 5-10 minutes. If you start to run out of space that means you likely used bit too much water and should use less next time.
5. Once you're done, get the heck up and go detach the domes, attach the airlock while holding the tube shut again to avoid water getting in, release the pressure and use your hand to control the airflow back inside while leaning forward. Try to make sure that not much water goes inside the tubing. Remove the dome, pour water out and repeat on the other side. Detach what ever is plugging the lower end of the tubing, seal the end going to the pump, blow air inside the tube to empty all the drops and then plug the lower end again.
6. dry your lovely titties and use lotion on them to avoid your skin drying. There's amazing skin care product called Bio-oil which you can use for this, its perfect for also curing discoloured skin, adds elasticity, fades dome edge marks and it smells awesome.

Its also expensive but a 200ml bottle lasts for ages.
There you have it. Go noogle, make them BIG.