Reddit mentions of Ibanez MTZ MTZ11 Quick Access Multi Tool, Red

Well, if they're all doing it, then they all need a proper set up from top to bottom, but you should learn to do it yourself. Thankfully, you have one of each of the most common types of guitars/bridges out there, so you'll learn to set up virtually any guitar you come across.

To do set ups, you'll need a few basic tools, but they'll cost less than a single set up for just one of your guitars. All you really need is a notched straight edge, a fret rocker, feeler gauges, some allen keys and screwdrivers, a good plug-in tuner and a small metal ruler capable of measuring in 64ths of an inch/millimeters (the Ibanez multi-tool is a great gizmo that's like the Swiss Army knife of guitar techs and contains all of the most common allen keys, screwdrivers, truss rod nut wrench and a ruler). You can get all you need for about $50-$60 US.

https://www.amazon.com/Guitar-Notched-Straight-Edge-ROCKER/dp/B00O6KT5HO/ref=sr_1_5?ie=UTF8&qid=1519439907&sr=8-5&keywords=Notched+Straight+edge&dpID=41meBDYMqoL&preST=_SX300_QL70_&dpSrc=srch

https://www.amazon.com/Ibanez-Quick-access-MTZ11-Guitar/dp/B00F4SDYNS/ref=sr_1_1?s=musical-instruments&ie=UTF8&qid=1519439935&sr=1-1&keywords=Ibanez+multi+tool



As you've noticed, some of your guitars don't have individual saddles, like a Strat (just one of its many superior design features). On your LP, you can only adjust the overall action on the bass or the treble side by using the thumb screws under the bridge. I'm assuming the Tele has the "vintage" saddles where each saddle holds two strings. Again, you can sort of adjust the action of each string by raising one side of the saddle, or the other, but it's not very precise and you have to find a compromise between the two. The same goes for intonating the strings. The Gretch probably has a bridge similar to the LP, but I'd need a pic to be sure.

The good news is that it's not really the humidity. I live in Florida, in the US, and it's as hot and humid as anywhere and my guitars are just fine. The only time humidity really becomes much of an issue is when there are large swings and/or during the winter when you use lots of artificial, indoor heating which severely dries out the ambient air.

Generally speaking, the order of the steps are all the same for each type of guitar, but you'll need slightly different methods to adjust the action/intonation based on the type of bridge is on the guitar.

Steps:

1. remove all strings an give the guitar a good inspection and cleaning
   
   
2. make the neck perfectly level using the notched straight edge.
   
   
3. use the fret rocker to check for any high frets and file them down as necessary.
   
   
4. install new string and take note of the gauge you're using, then use that same gauge going forward.
   
   
5. check the relief in the neck by using a capo on the first fret while fretting the low E string at the 15th or 17th fret. With your free hand, check the relief at the 7th fret using a feeler gauge. Set the neck to the factory spec at first then tweak as needed. Most guitars have a relief of about .010" between the top of the 7th fret and the underside of the low E string. The feeler gauge should just barley make contact between the two. If it slide in without making contact, tighten the truss rod nut by turning it CW in 1/4-1/2 turns then re-check.
   
   
6. With the relief set, you can now set the action. Remove the capo and check the string height at the 12th fret by measuring from the top of the fret to the underside of the string. Again, start by using the factory specs. Most guitars have action at about 4/64th-5/64th, or about 1.5mm. On a Strat, you can set each string individually using this method, but on the other models, like the LP, you can only set the height on the Low E and the High E strings by using the thumb screws and allowing the other strings to be where they end up. Regardless, of the model, be sure to slacken the strings a bit before you adjust the action, then re-tune and re-check the string height.
   
   
7. With the action and relief set up, you can now adjust the intonation. Start by plucking the open string and getting it perfectly in tune with a good, non-clip-on tuner. Once set, play the 12th fret harmonic, it should also be in tune. Finally, fret the string at the 12th fret using normal playing pressure. If it's flat, the string is effectively too long, so you'll want to move the saddle forward. If it's sharp, the string is too short, so you'll need to move the saddle back. Make small adjustments and constantly check and re-check after each alteration.
   
   I know it sounds like a lot, but it's really not that bad. Just a bit tedious. However, once you get your guitars dialed in, they'll be good to go from here on out.
   
   Check out Dave's World of Fun Stuff on YouTube, as well. He's a super funny Canadian with tons of tips and tricks for setting up, repairing and maintaining your axe.
   
   Holler if you have any more questions.