Power-Up or Evolve First?
I know this is an old question but what is the best strategy?
1. power-up to max and then evolve
2. evolve and then power up to max
Answers
Evolve first so you know which moveset you get for free. You can then factor in the TM costs of your projects to the equation when choosing which ones to do first.
The stardust and candy costs are the exact same so if you have an infinite supply of TMs, it doesn't matter at all which order you do it in.
On that second point, more generally: any future split-evolution, especially the two that require a specific gender. That includes:
Three Eeveelutions (2x Gen4, 1x Gen6), male Ralts/Kirlia (Gen4), female Snorunt (Gen4), Pikachu (Gen7), Exeggcute (Gen7), and Cubone (Gen7).
https://bulbapedia.bulbagarden.net/wiki/List_of_Pokémon_with_cross-generational_evolutions
It really only matters in two very specific situations:
1) In the case of Pokémon who may have a divergent evolution in the future, like Eevee and Ralts, and you can't de-evolve or evolve into a different form at the same level (ie: Jolteon to Umbreon).
2) On Community day (or any future events with event-specific moves) when you HAVE to evolve the Pokémon during the event to get the event-specific move and you can't use a TM to get the event-specific move.
But outside of those two extremely specific situations, there is no difference between the two. Advice about evolving first, then seeing how many TM's it takes to get the moveset you want, is good advice if you need to conserve TM's, but once you no longer need to conserve TM's, it goes back to there being no difference between powering up first or evolving first.
(The only potential reason to do one or the other that I can think of is if you want to use the evolved form to battle while you're powering it up. I'm assuming that this isn't part of your as this question sounds like you've got all the candies and stardust you need, so the moment you evolve it, you're powering it to level 40. But if you were intending to use it between the start of the power up/evolve and the end of the power up/evolve, or it was a long-term project to power up to the max, then it makes more sense to evolve into the most useful form for battling first, then powering up. A level 20 Machamp is more useful in battle than a Level 20 Machop, obviously, so it would make more sense to evolve the Machop to a Machamp before powering it up if you were going to need to use it to battle before you hit Level 40 with it.)
