This lets you sneak attack a target without being hidden or having a flanking partner. Spells like Hold Person and Overwhelming Grief are particularly noteworthy because they deny the target its Dex bonus. You also have a number of spells that can make enemies easier to hit if they fail to save, such as Blindness/Deafness, Ray of Exhaustion, Slow, and Web. True Strike basically guarantees that you'll hit, though it only affects a single attack roll. Casting Reduce Person on yourself increases your Dex and gives you a size bonus on attack rolls. Cat's Grace gives you a +4 enhancement bonus to Dex, for another +2 to hit.

Haste provides is a full-party buff that provides both an extra attack and a +1 on attack rolls. Heroism is a nice, long-lasting buff that provides a +2 on many rolls, include attacks. Since opponents who can't see you are denied their Dex bonus, that further reduces the AC target you need to hit. If not, you'll need to be unseen to deal sneak attack damage for an Arcane Trickster, the obvious solutions are spells like Greater Invisibility ( Darkness can also work if you have darkvision). If you plan on flanking in melee, you'll get a bonus from that. For many enemies touch AC is much lower than their regular AC, so that helps a lot.

Even low-level spells like Acid Splash and Snowball allow this. Sure, you need to be hitting to deal sneak attack damage, but as an Arcane Trickster you'll often be able to target touch AC. I'm not sure that you need that high of an attack bonus.

Waying spellhunter