Demonstrated here are 3 EGO E-Cigarettes whith different styles of atomizer/tank tips. Each different style is modified with an identical method with the same results and with no modifications to the Ecig itself.
NOTE: It is my opinion this Ecig design is not the proper tool for producing very, very large vapor filled bubbles no matter how much you modify the Ecig itself. If you want to increase the air flow simply loosen the connection where the atomizer screws into the battery section for a tiny bit more air flow.
If making large "smoke" filled bubbles faster is your goal I recommend moving up to a modified Zero Launcher or Dragon Puffer available online through Zereo Toys, Inc. [EDWARD NOTES: This recommendation seems no longer to be accurate. Rick's updated 2015 design seems the equal of the Zero Launcher with much better longevity. See details here.]
It is important to mention the EGO style E-cigs are push button operated to activate the battery. When not in use press true button RAPIDLY 5 times to shut the battery off. The battery can be accidentally activated while traveling, etc. Repeat to turn it back on again.
Rick advises: the output can be significantly improved by poking some holes in the straw with a sewing needle. Ths holes should be made so that they will be inside the tube near where the straw meets the cap.