Some feats aren't as attractive as others due to a rather bland an uninteresting bonus. I've seen all the threads proposing that you scale these feats as you gain levels. While this fixes the problem of feats getting somewhat obsolete at higher levels, I would go one step further and grant yet another bonus to make the feat more viable at lower levels of play. Here are some ideas for fixes and scaling for some of the more common feats.
Weapon focus: Grant a +1 bonus to attack rolls with a certain weapon as normal. Every four levels after the first gain another +1 to hit to a maximum of +5 at level 20. Once per day re-roll a failed attack roll with a weapon this feat applies to.
Improved initiative: Gain a +1 bonus to initiative rolls, this bonus increases by +1 for every four levels to a maximum of +5 at level 20. Once per day you may reroll your initiative.
Great fortitude/Iron will/Lightning reflexes: Gain a +1 bonus to said save. +1 extra for every four levels after 1st to a maximum of +5 at level 20. Reroll said save once per day.
Skill focus: Gain a +2 bonus to one skill, +1 extra bonus for every 3 levels to a maximum of +8 at level 18. You may take ten withe given skill as if you had the skill mastery special ability once per day.
Stealthy/Acrobatic etc.: Gain a +1/+1 bonus to two specific skills, this bonus increases by +1 for every four levels after 1st to a maximum of +5 at level 20. You may reroll one skill check with one of these skills once per day.
Quick draw: In addition to the normal benefits you may sheathe your weapon as a swift action that does not provoke an attack of opportunity. (I implemented this change years ago due to complaints from my players that you couldn't sheathe a weapon quickly like seen in some movies and such)