Use an Eyelash Curler
Eyelash curlers increase the natural curve of your lashes, making them look longer even without makeup. Depending on how straight your lashes are naturally, the results can be dramatic. If you use a curler and makeup, the upward tilt will set and hold for hours. These tools look like torture devices, but they're actually easy to get used to and safe to use. Once you become proficient, try warming the curler (just a little) with your hair dryer. It works a little like adding hot rollers to your hair. You'll get lifted, arched lashes that will last all day.
Here's another tip: Even though eyelash curlers are usually applied to bare lashes, curling your lashes again after adding mascara will create a dramatic effect. Repair any damage caused by the curler with an additional layer of mascara. This is a great alternative to wearing false eyelashes for an evening out.