Never, never....ever let someone else ruch you so you paint yourelf int a corner.
Typical situation.You finish a days flying and heading towards your car to go home, 5pm at present and last night is 5.45. The boss comes out and says, can you get a plane down to woop woop for maint and it has to be there today. Its a good half hr flight, your not IF or night rated or current or the aircraft isnt.
That gives you 10 mins to plan and get going(plan preflight Wx and notams etc), before you run foul of last light. Then you cant find the MR or keys quickly, then find its only got the min fuel, on top of that you havent flown that type in a while. If you go you will scrape in with nly a handful of mins before the 10 mins before EOD etc IF.....everything goes 100% right.. Perhaps you also havent been to the destination for some time.
You feel the pressure, want to get the job done, the boss is putting the heat on you to get going, perhaps the engineer has rung up 3 times to say where is the bloody aeroplane that you said would be there that morning. Your tired, maybe a bit flustered. Nothing is going right.
Take a step back, a deep breath and just say you cant do it. This has happened a few times to me, and on a few occasions after starting up and getting to the holding point, and cancelled. I just wasnt comfortable, I felt my ducks wern't in a row as they say. Now some would criticise, .....commercial pilots are supposedto be able to get going quickly, but theres a difference between being efficient and being rushed. Dont be affraid to say NO. if you have to, just walk 100m away from the aircraft, its amazing how your perspective on the situation just by putting sme distance between you and the aircraft.