Some good things to know about pup...
The best way you can skill up varries per frame.
For melee- aim for enemy's that won't die but deal poor damage, and are able to cure themselves.
For magic - aim for enemy's that deal no damage but inflict status ailments.
For ranger - aim for enemy's that stay stationary with high damage resistance.

Or you can cheat...

Go to abyssea lathine or grauberg and equip x3 regen atmas and pull like 5-20 fairys with your pet, then Afk against a wall. Equip all the evasion and defense attachments you have. The fairys use tp moves that AOE cure all of them, and they spam curega and cures which will make it so u fight the same one for a few hours.... Works for all skills

Or

Recently I leveled my fourth puppet master and had 0 ranged skill and level 99 job...
The new adoulin enemy's are perfect for afk magic skill and afk range... Use the mushroom thingies that spam paralyze and leave ur ranged pet on it for a while, while you go to bed. Same goes for whm, the enemy will spam paralyze, and ur pet will spam Paralyna, if you can get ur hands on the h2h with refresh/regen from abyssea miser? Or vunk? (The NM near the clusters) and the delve cape with refresh, then your pet will have a 2 tick auto refresh. However, whm pet skills pretty fast if you take it with you on a few adventures!

As for frame/ attachment advice..
I love my valoredge pet! But everyone loves rangers damage so it is a good way to go considering u dont have to pay for ammo lol

All the attachments do the same thing, and they are all as good as each other one is, so GET ALL OF THEM. What I mean by this is there are 8 elements and each element has the same kind of attachment as the other element, they are just all situational. Example
Earth has attachments that negate damage
Fire has attachments that boost your power
Wind has ways to make you attack quicker, or evade
Light has ways to cure and remove status ailments
Dark has ways to recover mp
Thunder has ways to make attacks more accurate/gives you bonus attack types
Water is magic def bonuses
Ice is magic attack bonus

If you want a paladin / warrior use earth and fire attachments

If you want a powerful ranger use wind/fire attachments

If you want a powerful blackmage use ice/dark attachments

Ect

If you run out of elemental lights but really want to use an attachment,try swapping around your head and test it out!

Example;
A few years ago I wanted to equip both regen attachments on my valoredge pet but I couldn't because I didn't have enough lights, so I used the whm head and the pld body (his body gives him the ability to use weapon skills) and by doing so I can equip both regen and use optic fiber, now when I use x3 light maneuvers I have like a 75 tick regen (I forget the exact amount) and all of my other parts I have on are boosted by something like 15-30% due to optic fiber.

So puppet master is a job that caters to your desires for the situation, and eventually it's as easy as selecting which armor you want to wear! I have always said puppet master is a HQ bst lol I'm just hoping they might come out with some new attachments or frames ;(. A drk pet or a thf pet would be nice but I guess that's what we have bst for ;p