Not a full-out guide, but thoughts I work with when going for power (and usually I split something like 75-25 in terms of power/flavor options, because there are a lot of really cheap but really flavorful choices out there).
1. Never use anything but Humanoid and Outsider. Undead can be considered for a divine class under exceptionally high racial buy, but even then it's likely suboptimal.
2. Large is overpriced. Tiny is actually fairly good for some characters; you can subvert its largest issue with a simple Longspear. Medium and Small are still strong go-to choices though, for obvious reasons.
3. Advanced Stats. Every time.
4. Since you're choosing your languages anyway, Linguist is a waste.
5. Advanced <Attribute> is overpriced. They're functional as filler options if you're really out of anything else to take, but they are not strong options.
6. Defensive traits:
-Dual Minded is good as always.
-Eternal Hope is a sleeper: two points for a "save my sorry ass" ability is actually a decent trade.
-Greater Defensive Training looks decent but is outclassed; you can get +2 Natural Armor for three points.
-Hardy is actually not great; it's one point separate from Greater Lucky so it's easy to go with that one.
-Spell Resistance is very group dependent. I have a table where everybody took Greater Spell Resistance and it's worked out, but our buffer is going to be heavily investing in anti-SR tricks. For most tables, I wouldn't bother unless I was the primary/only buffer. Never use Lesser SR.
-Damage Reduction and Fast Healing are strong on paper but extremely overpriced. There are better options.
7. Feat & Skills Traits:
-Static Bonus Feat is a very strong choice; a feat for 2 RP is beautiful. That said, note the "no prerequisites" requirement; that might force you to the more expensive Flexible Bonus Feat. Some builds will do well taking both, though.
-Skill Bonus is rarely worth it. Skill Training can be, if you're missing key skills like Perception.
8. Magical Traits:
-The SLA traits are very hit or miss. They're often underpriced compared to taking those same two abilities with the Variable SLAs, but you might not want all of the abilities. Run the numbers and consider each one.
-Variable SLAs are stupid good, especially the At-Will one. We have a party member who took At-Will Vanish, which makes him a very good party scout. You can remove your need for a party healer with a mere six points for At-Will Cure Light Wounds and Lesser Restoration.
9. Movement Traits:
-Fast is a great use of that last one point that you just can't figure out where to drop. It's even a solid use of three points; a 50' base speed is nothing to scoff at.
-Flight requires a lot of point investment to be good. 6-8 RP is a big investment. That said, you can mitigate those costs somewhat by picking up the Slow trait (not like you need to walk, right?), and if you've got the points to spend natural flight can be a godsend.
10. Offense:
-Ferocity is expensive but can swing a battle. It's at least worth consideration
-Toxic is surprisingly decent for a class with a good Con score. I expected it to suck, but I've seen it put to decent use
-Weapon Familiarity is a really cheap way to pick up the Half-Elf "I really like Exotic Weapons" schtick. One point to use a falcata is a good trade
-Natural Attack is wicked underpriced. Screw Claws or a Bite, pick up a Slam or Gore
-If you're Large, you're taking Reach and you know it.
11. Senses:
-Darkvision is, of course, very strong. A full party with Darkvision has options that one carrying torches for that silly Human just doesn't. 120' Darkvision can also be strong if you know your enemies are banking on it; seeing them before they see you is a big deal. That one's gonna depend on how the GM runs things though.
-Blindsense for 4 RP is a steal. A Heartseeker weapon will let you bypass any remaining concealment issues, and then nothing can ever sneak up on you.
12. Other:
-Heroic is a sleeper if you're using the system. A get-out-of-jail-free card once per level is good if you're in a game with tough enemies and lots of race points to spend.
-Prehensile Tail is good, and even better if you're allowed to take its Grasping Tail feat upgrade
-Multi-Armed is obnoxiously expensive and requires lots of GM input on how exactly it will work in terms of things like Two-Hand Two-Weapon Fighting or Quad-Weapon Fighting. It's also obnoxiously powerful if you can afford it.
