Skill and weapon is more important, problem with archery is that it level up pretty slowly so you would do pretty low damage compared to your sword if you don’t use it on most of your attacks. However bows can be useful even at pretty low skill if you use sneak attack as you attack from a distance this is pretty easy, use poisons, enchant your bow with a decent damage spell. Booth poison and enchantment is independent of you skill.
One fun enchantment who works great for raising archery skill is drain speed 100 for 1 second. This will slow your enemy down so you can hit them more.

Yes, drain speed 100x1sec is a great enchantment on a bow for two reasons:

1. In the open, it will pause the target, giving you more time to nock your next arrow. With only one second, he will still make progress towards you, but it helps a lot. This is very helpful, but the real beauty of drain speed lies in the next paragraph:


2. Quote UESPwiki: " If a character's speed is reduced to 0 (Through Drain Speed or Damage Speed) not only are they rendered immobile, but they will cease targeting the player and won't try and defend themself if attacked, even if they have ranged attacks or spells. In this state they can be repeatedly sneak attacked from behind."
Your target goes 'stupid' for a second and 'forgets' you just shot him, so he will not look for you. What this means for my archer is that if she is well hidden when she shoots, she will be hidden from her foe after she strikes. The implications for spell casting are great here too. Her weakness to poison 100 x 5 seconds + drain speed 100x1sec spell means she can weaken her target to poison and remain undetected as she quickly then shoots her poisoned arrow. The tactics that can flow from this are pretty impressive.

Where can I get the drain speed spell from? I see Destruction has a number of Drain Skill spells but Speed is not mentioned.

You will most likely have to make it yourself. Getting one Drain Skill spell, will allow you to make a Drain Skill spell with any of the 21 skills.

If you have any drain attribute ability, then you can create spells for any of them. The tough part is getting the ability - there are no such spells for sale in Cyrodiil.

There are a few ways to get the effect. My preferred is to complete the Orerry DLC quest. All orcs are born with the ability. You can earn the ability in KOTN or SI and there is a glitch or two you can obtain it with as well.

It is very well detailed here: http://www.uesp.net/wiki/Oblivion:Drain_Attribute

OK, thanks for that information. I have the two expansions but haven't installed them yet as I wanted to play the game in its original form first, so I'll probably get the Orrery quest.

Sounds good. The Orerry quest is a simple one. The reward is one of several special powers - any of them provide you with the ability to create spells/enchant with drain attribute. Again, that's the way I normally get that ability.

On a PC, you can use the console to give yourself the Orc power which bestows Drain Attribute power. I did this for Angel. Just follow the link above to read up on the power and get the ID number. Then, check the console commands in the UESPWiki to learn how to add that power to you character.