dont be mate - i have been working on my own cars for years and still managed to drop it off its widow maker jack last weekend - luckily landed on the old disc that was being replaced!!!
If you slide the trolly jack in you can use the actual jacking point but I prefer to go directly in towards the middle of the car in line with the jacking point and there is an obv flat bit to use to jack it up. I then put the axle stands where the rear beam connects with the chassis, lower the jack on to the stands then I lift the jack up to the point where it just starts to take some of the weight again as a second defense (i get paranoid about the weight of a mk3 on my face)
others may do it differently - possibly better