At the most recent meeting of my RC club, several pilots got into a discussion about the embarrassment of accidentally flipping the wrong switch on their radio transmitter. The consequences of this mistake ranged anywhere from scuffed paint to a full-bore crash into the turf. Given the complexity of modern radios and the forest of protruding switches, it's easy to understand how even a seasoned pilot could mistake one switch for another. It is even more understandable when you realize that many pilots are reluctant to take their eyes off of their aircraft. The myriad switches are often navigated purely by muscle memory and feel.
Nearly everyone had a story to share about causing damage to a favorite model from an absent-minded switch throw. Most stories were followed by a description of what was done afterward to mitigate the risk of future mistakes. The majority of pilots chose to modify a critical switch in order to differentiate it from its neighbors.
For many pilots, their target switch to modify is the one which activates retractable landing gear. Obviously, you want to be able to easily locate that switch so that you can safely lower the gear when it's time to come in for a landing. This is especially true if you're already dealing with an in-flight emergency such as a dead engine.
Correct operation of the landing gear is also vital when the model is on the ground. One pilot relayed an incident where he intended to retract the wing flaps while taxiing his expensive jet model. He inadvertently hit the landing gear switch instead. As the landing gear tucked itself away, his jet belly-flopped onto the hard runway, causing considerable mechanical and cosmetic damage. Another flyer talked about the time he accidentally retracted a model's landing gear while the engine was warming up. His transgression ruined a very costly propeller.
Many multi-rotor models have switches that control flight modes and/or the 'return home' function. Changing either of those could fundamentally alter how the model responds to your control inputs. Correct positioning of the switch is vital.
Whatever your hot-button (or two) may be, the intent of modifying the corresponding switch is the same. You want to be able to quickly identify that switch by feel so that you can move it when you need to and leave it alone when you don't. What follows are three proven methods to modify a critical switch.