Some common culprits of lashes not lasting:
Oily skin and using skincare products containing oil - lash adhesive doesn't agree with oil!
Lack of cleansing - the eye area is naturally quite oily. Not washing the area means there will be a build up of oils secreted by the skin, and this will not only weaken your lash growth but make the extensions fall off very quickly.
Not rinsing off your make upremover - many clients choose to use an eye makeup remover using a pad or a makeup remover wipe. These products contain emollients to avoid drying out your delicate eye area. This film must be washed off afterwards with a foaming cleanser or it will have a similar effect to using an oil product on the eyes.
Excessive touching - playing with the lashes is fun but your fingertips contain oil (just look at the screen on your phone or keyboard on your computer) and you are applying oil every time you touch the them. Please leave them alone other than during your daily washing ritual!
Lifestyle factors - extensions never last as well on people who regularly sweat it out at the gym, go swimming, do hot yoga etc. You must be prepared to get infills more often than others.
Heavy makeup - extensions also never last as well on people who wear a lot of makeup (especially eye makeup) daily compared to someone who wears little or no makeup. More makeup means more products and more effort to remove everything.
Lash cycle - many factors including hormones, season and diet can affect the speed of your lash cycle. It is quite normal that sometimes your lashes naturally shed quicker than other times.
Lash design - the extensions selected may be too long and/or too thick for your natural lashes, causing them to twist or fall off prematurely. The design chosen may also not be well supported by how your lashes grow naturally eg. a cat eye styling when the natural lashes on the outer corners are very short and fine. This can be discussed with your stylist at your next appointment.
Please keep in mind it is completely normal and healthy to lose around 3 lashes per day whether you have extensions or not.