I am using a PICSTARTplus for in circuit programming.
So far I am removing Vcc from the programmer before
connecting the ISP plug from the programmer and removing the
ISP plug before powering up the circuit.

I could

- Presume that the 2 Vcc's are close enough and common the
Vcc connection (Murphy says this will kill the programmer
sooner or later).
- Not join Vcc's and allow the local supply to power the PIC
during programming.
- Place a diode in the Vcc lead from the programmer to the
circuit being programmed (probably Schottky (eg BAT85)).
- Mechanically switch the leads (yuk)
- Remove the plug as now (yuk yuk)

1.    What do YOU do?

2.    How many programmers have you blown up :-) ?