Part 3 of 4
For your Bow bar, I would go this way:
1 — Swallow Soul (Strive) or Evil Hunter (Expert Hunter)
2 — Poison Injection (Poison Arrow) — This is your ranged execute and is wonderful against a single target. It's the first thing you should cast on a single-target after opening from stealth with a long hit (hopefully from behind). If the mob does not die shortly after, then it's probably elite and then you need to swap to DW or Magnum Shot (Scatter Shot) yourself away from it in a backwards kite, probably in a circle.
3 — Scorched Earth (Volley) — One of my favorite things to do with a bow is to lay waste to up to a dozen enemies at a time using Scorched Earth and Bombard. I will explain how in the next spell.
4 — Bombard (Arrow Spray) — This spell, combined with Scorched Earth, is ESO "Easy Mode," but is so fun to use. The technique is to lay down a Scorched Earth on a group of mobs and, while its arrows are still on the way down, fire off one or more Bombards to "lock down" the group, forcing them to stay in the Scorched Earth. Shit dies fast (assuming you use my build). You can kill giant groups of enemies with almost no effort.
5 — Magnum Shot (Scatter Shot) — For those times you need to GTFO... big, nasty elite is about to take a swing at you... fire this and he cannot hit you... for a moment.
Ultimate — Choose an ultimate from whichever skill line is lagging behind.
Evil Hunter (Expert Hunter) — I put this in my 1 position because I have it, it's a short-term buff and it's superb even just for the Major Savagery buff. The fact that casting it makes your weapon glow is a "kick ass" bonus. It requires Fighters Guild level 6, so it might take a while, maybe until your late 20s or early 30s unless you focus on leveling that skill line. The way to do this quickly is to farm Undead and/or Daedra. You can do this fairly quickly by farming Dolmens, making sure to tap as many spawning mobs as possible with your bow for more kill credits. Or, if you are in the Aldmeri Dominion, you can repeatedly clear the Mehrunes' Spite delve, which is full of Daedra. If you are Daggerfall Covenant, there are a ton of Undead around the graveyard in northern Glenumbra. I don't remember any good farming spots for Ebonhart Pact. I am sure you can find something online.
Spell weaving — With a few exception (like after Ambush), you do not want to be casting spells on your action bar one after another. You will get far more dps if you add in or "weave in" a basic weapon hit between spells. There are three levels of weapon hits: light, medium and heavy. A light hit is when you just tap your left mouse button. A heavy hit is when you hold that button down until the weapon either finishes its swing or, in the case of bow, the animation has stopped and your toon is waiting for you to release. A medium hit tends to be the most efficient as far as time spent casting compared to damage done (same as a heavy hit since it technically is one), at least in the middle of a fight. You will have to practice finding that sweet spot of timing for a medium hit. It's easier with some weapons than others. I find a flame staff to be the easiest to judge. You want to hold the left mouse button down long enough for it to not be a light hit, but not so long as the animation is completing its full cycle. About halfway is just right.