The traditional upper-lash application, made by rotating the mascara wand as you round-brush from the base of the lashes up to cover all the lashes around the entire eye is the most efficient, expedient method. Keep an old, cleaned-up mascara wand in your makeup bag to use for removing occasional mascara clumps (it can happen with the best mascaras) and separating lashes.
Apply mascara to the lower lashes by holding the wand perpendicular to the eye and parallel to the lashes (using the tip of the wand). This prevents you from getting mascara on the cheek. It also makes it easier to reach the lashes at both ends of the eye. If you want a softer application on the lower lashes, wipe the wand down with a tissue and then apply lightly.
Have you ever had mascara end up on the eyelid or under the eye while you’re applying it? Wait until it dries completely and then chip it away with a cotton swab or your sponge. Most of it will just flake off, with very little repair work needed. Always check for mascara smudges; they can look very sloppy and distracting.