When choosing a micro you should have an idea of the pins, memory etc, iow what can the micro do, and see which peripherals it has. Also, is it suitable for most other projects you may want to do, because if you can use the same pic in 10 other projects then you can keep a few on hand, the software is easier and save a lot of time.

In my case, one such a pic I'm using is the 16F684 and have used it for probably a hundred different projects. Another nice is it has the same structure as the smaller pics which MPLab complains about, and off late refuse to program with the int osc no clock out. Instead I select it as the 16F684 and program them without problems.

I also have one particular PCB I have been using for so many projects, and with a bit of peripheral vision you can make life a lot easier. I use 3 A/D's to read the keypad with, but the A/D inputs can be used for other functions as well, if you add a solder pad for instance for a pot, or switch if you don't want to use the keypad, or even share the pin. Also, one of the outputs drive a MOC and a triac for mains applications, the same output's layout can also accept a photo voltaic driver (EPV191S) to drive a FET or IGBT, which I just flip 180 deg so the gate is where trigger of the triac would be.

Many options, unfortunately one pic cannot do everything and one board neither. We're not that good yet, but we're working on it.