General

The best way to go is to back up beatdown single tick, and than release for it to deal the bonus damage...

this thread makes em miss suborbital bombardier

Depending of your funding, this is the moveset you should be using to clear mobs the fastest way possible.
(Low funds).
1. Release Backup Beatdown. You can also use comic upheaval to grab monsters behind/above you.
2. Starline Three (slower, more %dmg than Starline Four)
3. Starline Four (faster, less %dmg than Starline Three)
4. Starforce Salvo for small maps, Spacial Shift for bigger maps.
(Funded)

Take note you can jump attack with good timing or use what SilentLeaf55 said before me. You can use Vortex Jump to get closer to mobs near of you or you will move toward if there is no mobs. For any of those previous numbers, you can use planet busters to reach further mobs.

[quote=Kiryuin]
i think backup beatdown is good essentially the best way to go for coverage, but i see a lot of other jett's just using starforce salvo (they usually cap)
advice please?[/quote]

The number of high level active jetts is really low. It's already rare to see a funded Jett, but capping on starforce salvo on mobs requires around 7m clean range, which is uncommon. If you saw any of those jetts, it doesn't really represent the average mapler in training maps.

Against higher HP mobs, Backup Beatdown is the way to go if you aren't capping, with a few Planet Busters thrown here and there when it's available. Unfortunately, the Starline combo isn't exactly practical for mobbing since it's too weak, but Starline Four can move mobs around as a rush-type skill. It can also be used to clear trash mobs too like in DIPQ or RA. SL3 is too slow, and SL1 is only really good for 1st-3rd Job damage when hotkeyed (it gets stronger as SL2, SL3, and SL4 get leveled).

One tip to keep in mind is that you can use Vortex Jump (1st Job) to move after releasing BB. Useful if you need to approach mobs ahead of you or behind you. You can also use VJ to move after a Buster, or during Singularity Shock. Take note that VJ will autotarget mobs in front of you even if you hold back, so if you're using Shock against a boss, try to make it so your back is turned away to them to escape with VJ (easy to do if you jump past the boss while firing off Shock in the air).