Many people advise applying mascara before the lashes, however I often find that this makes application more difficult. The mascara makes the natural lashes stiffer, causing them to be inflexible during application.
Applying mascara after fake lashes enables the lashes to blend in more seamlessly with your natural lashes. It can also help to disguise any accidental gaps between your natural lash line and the fake lash line.
I would also advise using false eyelashes with a thin and flexible lash line. This will enable you to get as close to your own lash line as possible and will help the false lashes blend in even more effortlessly. The easiest eyelashes to apply are the super affordable Ardell Natural lashes (£3.98 Sally / $3.99 Ulta).