Glue Class

Sorry...this isn't a class guide, this is the place to learn how to make your janky combination of class ideas somewhat fit together.
Since there are almost 0 classes that don't need to be combined with others to be effective, and not everyone wants to make a perfectly min maxed class combo, here are the feats that help min max everything.
Unique Attack and Patron of War - If you aren't using STR as a primary stat, and you want to deal melee weapon damage (or have the Mighty Archer feat), this feat lets you use another Stat for damage rolls with weapons or unarmed. If you are a Spellcaster who wishes to use a Physical stat for spellcasting (STR, DEX, or CON) take the Patron of War feat.
Unique Perspective - EVERY character should probably take this feat at some point or another, but you can only take it once. You may change the Stat that is used for 3 different Skills or Saves. Very useful for getting combat utility for characters that don't use STR or DEX.
Mutation and Unnatural Ability - If you need spells that are technically cast as Supernatural Abilities, in case you're prohibited by a feat you have, these feats grant spells. Mutation has no requirement other than CL, but has a very limited selection. Unnatural Ability requires one of two skills for each kind of magic skill, so check which ones you want the most to ensure you have the necessary Focused Skills.
Focused Skills, Orphanage Trained, Favored Arms, Knowledge Specialist, and Master of Weapons - Need a Focused Skill to qualify for a feat you want? These feats have you covered. Focused Skills covers everything, the others only cover specific skills/skill groups.
Need a Stat Buff? Take Strong, Wise, Agile, Tough, Charming or Smart...you should've taken at least one of these around CL 2 or earlier.
Mental Specimen and Physical Specimen - These feats increase your Saves, if you keep failing them you should take these at some point
Chonky Baby, Chonky, and Extra Chonky - Need HP? These feats are your boys