There are a few key things to consider when making a ring-set, more so for solo-play than for crew play (since obviously in crew play you have team mates to make up for any shortfalls in your own ring set).
There'll be 3 sections to this guide:
1st off is an introduction to the "Generalist" build, and how to make use of the Ring Guide to fill in the slots of the build.
2nd is a couple of interesting (and probably dubious) mathematical points to consider when comparing the "Generalist" to some of the other ringsets - for example: " It doesn't have enough attacks! "
The precise order changes depending on whether you're utilising sets or how you like to play. That's more or less the order I use for my own set.
Choosing your Attacks
Chances are, if you're reading this thread it's because your set is running more than 3-4 attacks. So the thought of running less is possibly a strange one, there's a good mathematical reason (see post 2).
Which rings are best, depend largely on how you play. If you like to mob wildly, then Fire Rain and Dervish are going to become more efficient. Otherwise, Hack and Mantis are going to be the kings of attacks. You'll possible also want to run a ranged ring to lure - unless you love your mobs!
It's worth noting, however, that AoE and Ranged rings do require a bit more care than Melee rings, since they're a bit more specialised. Make sure you're getting the most out of them when you use them.
You'll probably want to pack between 80 and 100 damage per second. You can work out your builds DPS by dividing the average damage done by a ring, by the stamina cost of the ring, and then adding all your attack rings together.
Choosing your Healing
You have your choice of Bandage, Bandage or Bandage. If you choose Diagnose, make sure you're packing a LOT of buffs. A full discourse on how ridiculously bad Diagnose is can be found here.
Choosing your Buffs
Your buffs should support your Attack choices. If you're going mobbing with your attacks, then consider buffs which minimise the amount of stamina you have to spend on healing. This means Meat, and strong defensive moves like Rock Armour, Improbability Sphere or Pot Lid.
If your set is more ranged rings, then you're obviously going to be wanting to exploit the distance between you and the foe with a Coyote Spirit, and possibly run Healing Halo so you don't have to stop to heal (healing interrupts your movement action!).
One common discussion path is Pot Lid vs Improbability Sphere. Pot Lid is a bit more likely to occur, say about 4 attacks out of every 100. However, Improbability Sphere also boosts your DPS a little by turning the enemies own attacks against them, and it has some powerful combinations in Healing/Retribution builds. Personally, if you're going to pick one of the two - Improbability is probably your best choice.
Regardless of the path you take though, Divinity is a valuable ally. Running out of stamina is anyone's bane, Divinity minimises the time you spend on the ground waiting.
Choosing your Misc
Don't have enough buff space? This is your extra buff slot. Don't have enough attacks? This is your extra attack. Not healing enough? GET MORE BUFFS.
But seriously, this misc is to fill up whichever section you feel there isn't enough space for. Personally, I use it as a Crowd Control ring, for those horrible situations where you just can't kill things fast enough.
If we take a look at the stereotypical bad ringset ( "SADD" ), we're generally looking at six attacks like:
Hack (4), Dervish (5), Fire Rain (10), GGGuns (2), Shark (5), Fail Whale Heavy Water Balloon (6).
This gives you an average of ~24 Damage per point of Stamina. So you're looking at 2,400 damage at C.L. 10.0 if you swing wildly and don't spend anything on healing.
Sounds reasonable, doesn't it?
Well, lets have a peek at my ring set: I have 3 attacks. Hack (4), Slash (3) and Solar Rays (3). Average damage per point of stamina? ~35. We're talking about 1000 extra damage, just by shaving off the rings which aren't as strong, and replacing them with buffs.
Now obviously, nobody is quite dim enough to just fire off 6 rings willy-nilly until their Stamina is drained, but it's food for thought. I mean, if you're not routinely using the extra attacks then maybe it's a good idea to use those slots for something like a buff. They don't notably increase your ability to kill stuff.
2. Staying Alive
Obviously, if you ringset doesn't keep you alive it really isn't doing it's job. Some players rely on two healing rings to do this, I personally think there's a better way. Lets see what the math says.
Diagnose + Bandage = 65 Healing per Second (50 of this is courtesy of Bandage). Of course, lets not overlook the fact that you've only got 100 STA. That's 3250 damage you can heal max. (Using the average healing/stamina)
A Barnacle Fluff will do ~50 damage per second, depending on the difficulty of course. (400 damage, every 8 seconds)
So yeah, that build can outheal the Barnacle Fluffs, for about 8 attacks. Lets crank down the healing though, use Bandage - but combine it with Rock Armour.
The fluffs are now doing... 264 damage (thank you, RR4) , so we're now talking ~33 damage per second. Not only will Bandage ALONE outheal this, but it'll do it for: ~18 attacks.
You're still using two ring slots, but you're able to stay alive a LOT more effectively. And Rock Armour doesn't really eat into your Stamina, since you can always apply it outside of battle!