The Conjurer is easily the best soloing class in the game. If you invest in your pet and get an adept 3 or master pet, you can pretty much solo all the way to 80. I did this with Jayne, seldom grouping and questing only and got her to 74 without having to rely upon groups to get my levels.
Having played both a conjurer and necro, however, I found the conjurer pets were able to take more hits (with fighter pet) and not die as easily. They also hold agro more, even if I'm nuking with my top spells. You can help your pet hate factor and its ability to hold agro if you get an adept 3 or higher of the special defensive ward buffs you get with each 10 or so levels: Volatile Brace, Volatile Refuge, Volatile Haven, Transient Haven and Temporal Haven. Be warned though, if you have Adept 3 or Master versions of these spells, your pet will sometimes steal agro from your main tank -- not that your pet can't handle it, he can. But it may irk your tank if you're in a group.
Do not waste your money buying both the scout and mage adept 3 pets with each level, but DO invest in your fighter pet if you plan to solo. If you plan to group a lot pick EITHER your mage (fire) or scout (water) pet as adept 3 or higher for dps. The scout pet tends to die a lot, the mage pet has some powerful nukes, so if you were to pick, I'd nudge you towards the mage for DPS.
Also invest in an adept 3 or higher pet heal -- it's worth the money. And if you can, buy Adept 3 or higher of the Conjurer's Signet lines.
At higher levels you will get extra temporary pets to fight with you -- they last about as long as the duration of the fight and then die. Dig deep into your pockets, if you have ANY money left, and get Adept 3 or higher of these lovely little minions: Aqueous Stalkers, Aqueous Hunters, Aqueous Swarm, Aqueous Horde, Roaring Flames, Pyrotechnic, Pyromancy. It's like having a whole group fighting with you .. all the time.
And if you put some AA into your STR line to get the fighting daggers, you get yet another pet to help you in your fight.
This class is unfortunately really expensive to play - from wardrobe to the cost of buying adept 3 pets. Basically: Expect to feed your conjurer by robbing all your other toons. However, it gives you a remarkable amount of independence.
A helpful tip, though, for fighting in groups. If you're using your tank pet in a group and you're hit by a trio of mobs, off-tank with your pet -- meaning tank a mob that your lead main tank isn't hitting to kill or reduce the number of hits your main tank is taking. If you're using a DPS pet, target your main tank and fight through the main tank.
DPS pets work better with the offensive buff (instead of the defensive buff) you get every 10 or so levels: Agitation, Provocation, Vexation, Aggravate and Exasperate. Again, depending on how often you use your mage (or scout) pet, you can pick whether to invest in adept 3 spells or higher, but I would suggest against it.
AA LINE:
The first place you want to start putting in your AA points is your pet class augmentations on your conjurer page, left side. It gives you places to upgrade your fighter, mage and scout pets. Get a total of 20 in that category and you can get the SUPER cool hydromancer pet -- which is essentially a port-a-healer. It's a siren pet that heals you and your group members constantly. It's brilliant.
After that flip over to your summoner page and start putting your AA into pet enhancement spells -- starting with (believe it or not) your WIS line. (Wis helps you heal your pet better).
This line gives you pet enhancements that will prevent it from dying as quickly with the following two upgrades:
Minion's Barrier - Increases defense skill for the Animist's pet
Minion's Uproar - Increases casting and combat skills for the Animist's pet
These two buffs work on all pet types -- mage, fighter and scout.
I would max out the two above to 8 points, and do minimum on the first and second spell in that line.
Animist's Transference - Transfers health from the Animist's pet to an ally -- it doesn't heal you all that well, especially at higher levels and is not worth investing too much into.
This AA line also leads to: Animist Bond - Allows the Animist's pet to consume power to prevent the loss of health for a short duration, which is a wicked spell, but should be saved until you finish up the next suggested AA line: STA.
If you are soloing a lot, invest some AA points in the STA line, otherwise known as the "Keep the Conjurer alive" line.
You get spells like:
Shockwave - The Perceptor commands their fighter pet to knock down all enemies surrounding it after its next successful melee hit
Perceptor's Bodyguard - Allows the Perceptor's pet to protect their master, sometimes absorbing some of the physical damage the Perceptor would otherwise take
Perceptor's Command - Your fighter pet absorbs some of the hate that would have been directed towards you
Unflinching Servant - The Perceptor's fighter pet becomes immune to most knockbacks, stuns, and all area of effect abilities that do not directly target it. However, the Perceptor's pet also cannot use any of its combat arts
The STA line only works with your fighter pet tho.
After you have filled out these two lines, you can randomly put your AA points wherever you like.