the key to presto is Temporal anomaly , stasis and Lifebind.
Lifebind
Lifebind links the evoker and the targets incoming heals together so if one gets heals, the other 1 gets a % heals. The joy about this skill how ever is that you may use it through echos, it is extremely nerfed as to what it was in season 1 but will still pump out an immense healing number when combo’d.
Combo with lifebind can work as such… TA to get your echoes out… use all your echoes on more targets, verdant embrace to a target to pop lifebind for 8seconds… In this window you have a plethoria of tools to heal those targets. This toolkit includes the following. Dream breath increased because of Verdant embrace use. Spirit bloom enhanced becasue of tier set. Living flame, only fires one off but with leaping flames can fire 4 extra off which can all heal all targets if they hit targets of lifebind, Lock cookies, Healing pots. Emerald communion. Technically Emerald blossom, which does work, especially with the seed stuff going on but thats just practice to learn about that.
Empowerments
Ontop of that Presto is unique from Devastation but rather close to Augmentation when it comes to empowerments. You need to understand how fire breath and dream breath works. its not complicated but a rank 1 from a rank 4 can make or break you on the healing meters. Presto is essentially a heal over time healer. Rank 1 Dream breath heals the exact same as rank 4 Dream breath. The only reason you empower it is to have a more direct heal upfront. Lower ranks have longer hot durations, higher ranks have less hot duration. (this is exactly the same for fire breath aswell).
Most of the time it is perfectly fine to use rank 1 Dream breath. Tip the scales will automatically cast it at max rank however. Spirit bloom should be the priority for this as its a higher number and a hot with tier. Spirit bloom this season is a core part of your rotation. 20second spirit blooms will also make a massive dent in charts. Knowing when a chunk of damage is coming out and firing of a spirit bloom at the exact time fantastic vs firing it off early feeling bad or late and the heals are sniped.
Dreamflight
Dream flight is really your major cooldown, Rewind is great but its very limited as to requiring damage to have happened and chip damage like dots or small boss chunks not working. (think rashok intermission, it chips at health not chunks). Rewind will also only rewind the past 5seconds of damage, anything outside of that window is forgotten. So if there is a burst, Rewind is king, but if there is just chip, Dream flight is king. Dream flight does not require the full flight, just people under its initial take off and flight duration. So if everyone stacks like they should in a raid, throwing a dream breath during a rashok intermission is going to overheal the raid but leaves a massive hot ontop of them that helaing wont matter for 8seconds. In those 8seconds throw in some dream breaths and spirit blooms and a few emerald blossoms and you will be #1 by far.
Stasis
Stasis, stasis is a core management skill. Its something you wont get the most value out of in combat, but as a safety net you can set it up with 2 charges before combat and an extra charge 5seconds before combat and you will usually cover the first major aoe damage of the raid with it. Before pull it is extremely important to use Temporal anomaly 2 times in the charges and depending on raid size a third or if below 16 players a verdant embrace. This might sound weird but TA pops a 20k shield on targets. It also increases the shield size with each TA ontop of it (usually doesnt happen in combat but Stasis allows this to happen). This also spreads echoes to targets allowing for better life binds at the start of the fight.
Lastly stats, Mastery is great but ive seen people do Crit mastery and haste mastery. I did crit mastery season 1 and dipped towards aug in season 2 so went haste mastery. Both of these stat combos are good for aug as an off spec dps, crit mastery how ever leans more towards Devastation as haste is apparnetly useless for them atm? Idk the workings of dev. Haste does not effect your essence regen but does interact with your living flame fishing for essence burst procs.
Presto has 30yard range on all its skills except for dream flight and rewind. I do think Dream breath is 35yards aswell but some one will need to fact check that, it just feels like it.
TA applying echoes to the first targets it comes into contact with. I think it also has a 40 yard range (correct me if im wrong) but applying those echoes to the melee while standing at ranged can be complicated. Stasis basically promises it at the start but positioning yourself out of the ranged group to teh side or behind them is extremely important.
Out side of that you wont really notice the range issue happening often and when it does you have hover to reposition yourself better.
Otherwise GOODLUCK!