The main two enemies of the adhesive are oil & cotton. Cotton's fibers get stuck in the lashes and may yank out the natural lash. The fibers also extremely hard to get out of the lashes once they are intertwined. Oil breaks down the adhesive. Avoid any oil use below the brow line. Cover the lashes before using any type of oil-based spray.
Avoid any activity that puts undue pressure on the lashes. This includes splashing water on the face or standing underneath the shower.
From now on, wash your face using a washcloth and wipe around the eye area. You may consult with your lash artist about special lash cleansers that you may use with your extensions if you wish to clean them separately.
If you choose to wear makeup, especially eyeliner, make sure that it is oil-free. The best eyeliner to use is kohl liner, or powder liner, as it is water soluble. Basically, choose one that is easy to remove and will not require excessive rubbing at the lash line.
Make sure that all removers are oil-free as well. Many people use micellar water or Neutrogena.