For people that are just using kapton, i use a can of compressed air duster. Just spray it on the bottom of the part and it releases right away. For stubborn parts you can turn the duster can over and have it spray the liquid and works better, though this cools down your bed a lot a may cause the bed to warp due to the quick change in temperature. Ive also used a compressor but its a bit strong and blows stuff all over the place. Blowing on the parts with your mouth works too but i get really light headed after a while. If you are using clear filament you can actually see the parts releasing from the glass/bed.

The duster cans are a bit expensive so i find that the glass/water method is the cheapest and works most efficiently.
Hope this helps someone.

I tried the same print (attached in this post) again and it unstuck at about 80%. It is a tricky print since it doesn't have a lot of surface to stick but it printed fine with kapton.

I have also had great results with cooling the glass - initially during the winter by placing the glass near a slightly open window for a few minutes - and now, just by setting the glass on a re-purposed PC fan.  I also tried using a 2"x2" Peltier plate (left over from my laser-fun days) with decent results, but one piece of glass cracked during cooling - perhaps from the uneven cooling pattern.

Considering most of my parts aren't even visible in many of my models, and the bottom of the print is usually the bottom of my model, I did happen upon a nice method.  I erroneously bought 100mm wide kapton tape.  Set it up so that the seam between the 2 pieces of tape was right down the center of the glass, and the super-slight gap does help to remove the prints.  I did experiment with a small 2nd layer of kapton as well, when I was printing a dozen of the same big part, and that helped too, but was an annoyance to manage.

good luck.

i had one large PLA print stick so well the other day that the glass shattered as i was trying to pry it off. so some caution is in order! lol

I agree with your post on glass+hairspray, but the one thing I didn't hear you say that would have saved your glass plate:

Put the plate directly in the freezer with the print. The glass will cool much faster than the PLA and the difference in temperature will cause contraction, and the PLA will pop RIGHT off, no problem, in under 10 minutes. Zero chance for breakage, or scraping the glass.

The only way this could not be preferable is if you only have one piece of glass and your bed takes a looooong time to heat.

http://www.thingiverse.com/thing:28787

ABS or PLA, glass + hairspray is the answer to what ails ya. lol

one very common mistake is to start the print before the whole heated bed + glass assembly has come up to temp. remember that its going to take a bit longer for the bed heater to heat the glass as well. and take this into account. i simply added the M190 command to my start Gcode so that the printer wont even start moving into position to heat the extruder until the bed is up to temp. seems to totally solve that problem.

also, experiment with several types of hairspray. the cheaper the better IMO (you don't want "organic" or any crap like that, you want the sticky icky stuff that makes your hair fall out.) if one doesn't work, make a note of it and move on. thinned down white glue (elmers) can also be painted over the bed, then to remove the part you can just run the cooled glass/part under water to dissolve the glue. i haven't tried this yet, but i will be experimenting, because i had one large PLA print stick so well the other day that the glass shattered as i was trying to pry it off. so some caution is in order! lol

The good part about the glass bed is if it doesn't work, you can revert back to your old setup by just pulling the glass off and reset your alignment. No need to touch the existing setup at all. The only thing you've lost is $2.50 worth of picture frame and 3/4 bulldog clips. Both of which can be reused if you keep the rest of the picture frame

I've heard about the glass bed before but I didn't know it was so simple. I may try it but I did hear about it not working so well for larger prints.

There are plenty of people here who are more than willing to help out if you have any problems. Having said that, im sure others have gotten the kapton to work better than I did.