I personally use the 1-2-3-4 method. You use 1 N, 2 R, 13 SR (totally the same as 3, right?) and 4 SSRs. All of the same element. That gets you halfway to level 50, so if you don't get a Super Success, you need to do it twice.
Now that you're getting two SSRs per run, you might overflow with SSR fodder. In which case, you can swap 1 SSR for 2 SRs (ideally for the second Enchant to save money). So for example 1 N, 2 R, 1 SR, 10 SSR is halfway as well.Sadly, it is useless. You need 10% to gain 1 more burst per hit, so you'd gain 11 burst per hit then.
Well, the way it works is that if you do a Double attack, then 5% is enough for 1 more burst (so 21 burst per double hit) and so on but... well, as you can see, the gain is just too small when the maximum burst you can reach is 100.In my opinion:
SSR Tiaras are #1 priority. Everyone needs 3 of these for the Tiara Set Bonus when you have all five slots opened. Two good enigmas is good enough.
For non-Tiaras, don't bother with anything less than 3 good enigmas OR for debuffers, Affliction (the broken shield symbol). Only Ancient Tiaras can get Affliction chance, so having 4% from your non-Tiara slots is very valuable.
As for good enigmas, if you ask me it is:
Affliction (for Hime that can use it) > Def > Dbl/Trpl > Atk.
The rest are bad. Technically you can use some of them (such as Heal+ on Healer or Ability+ on a multihitter Hime) but in general, they're bad and should be ignored.