1. The zealous scythe really helps. It gives you a good amount of energy if you are having problems. The enchanting mod also takes some pressure off you by lengthening the time you have to recast.
2. Don't just go with what PvX says. Study the types of skills your target(s) are using and make a build that fits.
3. Make sure the mobs you are facing don't have enchantment removal. Also, make sure they don't have heavy degen because that can kill you.
4. Don't aggro too many enemies at once. If too many enemies are hitting you, they will overwhelm your regen and you will die.
5. Avoid enemies with interrupts and knockdowns. Both of these can stop you from casting your vital enchantments and can kill you.
6. Dying once on purpose can bring your health down to 58, giving you a better chance of survival.
7. When aggroing small mobs, consider doing the farm in Hard Mode. The faster these enemies attack you, the more energy you gain. I know this kinda contradicts number 4, but youll have to find the perfect balance between high energy and survival.
Once again, vary your build. When farming bosses, I use a build that looks something like this:
[Protective Spirit][Mystic Regeneration][Shield Of Absorption][Asuran Scan][Radiant Scythe][Reaper's Sweep][Essence Bond][Balthazar's Spirit]
Radiant scythe gives a nice high damage (only use with full energy, which shouldnt be a problem), while Reaper's sweep just pwns. Those 2 combined with asuran scan and you will be taking down bosses in no time.
Happy farming!
EDIT: Just saw the last sentence. This is a farming build, used for farming enemy mobs and bosses solo. Therefore, the only way for this build to work is if all the enemies are attacking you (you gain lots of energy that way). If you are just trying to do normal PvE, Pug (yes i said it, new players dont have the best heros so they have to pug) or H/H it, and go with a normal dervish build, preferably something that has to do with [Avatar of Lyssa]. (uber damage)