For abilities...

For the early levels...
1. Maker's Muse
2. Sure and Steady (or Fulfillment - same thing)
3 and 4. Aspect Balance if you're having trouble with the elements/sparking, Make the Most if elements are fine but you run out of durability often, Masterpiece or Pride of Labor if you're doing just fine. Alternatively, use whichever of Sure & Steady / Fulfillment you haven't already got in place.
5. Brand of ____

Level 25+
When you get things to 25+, you'll be able to use five skills. When you get things to 30+, you can get access to the better skills. Personally, I prefer going for something like this...
1. (Quality). Something that increases quality for the next three turns.
2. (Progress). Something that increases progress for the next three turns.
3. (Advance). Something that increases progress with no loss of durability.
4. (Durability). Something that increases durability.
5. (Brand). Brand of [Element], as when I craft to level, I like to push careful a lot and it usually results in elemental instability at some point. This can be a life saver in such cases, and sometimes can boost quality by 100 if you play your elements right for the craft. Some might say that Brand is a waste of another ability, but when I craft I find that elements go unstable often enough when focusing on quality that it warrants this. Perhaps when at L50 it's not required, but when you are doing crafts 5-10 levels over your crafter level, it's likely you'll need this on every few crafts.

Level 40+
If you get to the 40+ levels, I don't think you'll need any more help from us - you should be able to look at the skills you have unlocked and know exactly what you need and when.

Progress Targets
For me, I like to keep in mind a couple of progres targets. The initial target relies on the final target, so I'll explain them 'backwards'.

The final target is key - it's 100% minus whatever you can get out of (Advance). So if you have a skill that advances your progress by 20%, your final target is 80%, because you can just advance the rest should you run out of durability. Your main aim will be to get to 80% before you get your durability below 10-12.

Your initial target is generally around 30-40% before your final target - basically, this is where you want to get to and feel comfortable that you can just use careful for the rest of the craft.

How I Craft

I'm by no means an expert at all, but I do manage 250+ quality on almost all my crafts, even those 8-10 levels above my crafter's level. Crafts around 5 levels up I hope for 300+ quality without question (so basically all leve crafts). I like to think I do okay!

Firstly, I use my quality bonuses on thre carefuls early because I hate not having used them later on should I come into trouble with elemental instability or just really poor luck with standards. Secondly, I progress via standards to my initial target, at which point I know that I should be able to use carefuls exclusively from that point onwards (assuming elemental stability). Thirdly, I do those non-stop carefuls knowing I'll pass the final target. Then I do what carefuls I still can before (if neccessary) using the advancing ability to finish the craft.

In detail...

Stage One: Make Use of Quality Before It's Too Late
1. Start off with (Quality) and do careful for three turns - even if it goes unstable.
2. If element does go unstable, use (Brand) after the three turns.
3. If the colour is red or rainbow, use (Durability), should you have something that does this. Hopefully it changes to white or yellow, which I find to be better. If you don't use this now, you can use it later,

Stage Two: Get to a Reasonable Position
4. Use (Progress). How you play the next three steps depends on the individual, but basically you are looking to get to your intial target (something like 30-40% less than your final target) using Standard, and then use Careful after that. How far you go depends mostly on your skillset - you should get a feeling for how far you can push your luck on this end.
5. If element is unstable, still do standard or careful for the three steps as you don't want to waste them. Use (Brand) if you still have it afterwards. If it's a rare occasion that it's gone unstable twice, then consider yourself unlucky and just play things out as best as you can, because there's not much you can do but pray for good luck!
6. If you haven't used (Durability) yet, do it now, or whenever a red/rainbow colour next turns up.

Stage Three: Careful Does It
7. This is where I spam on Careful. Keep a close eye on your durability. Over time you should have a good idea how much durability each careful/standard will use up, and predict when you need to switch from carefuls to standards should your durability be heading down. Your intention is to reach your final target (and hopefully beyond, if you have spare durability) using careful synthesis. If your durability is too low or your craft goes unstable, switch to standards if you need faster progression.
8. It probably goes without saying, but if you come into elemental instability at any point from now and you still have (Brand) available, make use of it.
9. Once you reach your final target, if you have durability, use it up. If you don't have the required durability, use (Advance). Personally, my durability goes down by around 10 max for each standard or careful synthesis action. So if I have 11 durability left, I know I can keep going. If I have 10 durability left, it's a risk I'm not personally willing to take, and I use (Advance).
10. Don't Double Down. It's never worth the risk in my experience.