Side cutters (snips), a medium posi and flat screwdriver depending on the plug top, a Stanley knife and if you have them a pair of wire strippers.
Remove approximately 5cm of outer sheath from the flex, to do this score around the flex with your knife taking care not to cut into the conductors inside, just bend the flex at the score mark once or twice and it should pull off (fig1).
Prepare the plug top by unscrewing the top and loosening the cable grip inside. Now place the flex where the cable grip will hold it in place and mark the live conductor (Brown) for cutting, cut and strip sufficient insulation from the conductor to provide enough copper for the terminal screw to screw down on securely.
If you are connecting a small flex, say for a portable stereo, then it is good practice to strip twice the length of insulation you need and double back the copper conductor on itself, to give a better connection (more copper will help the terminal screw to achieve a tighter connection on the conductor).
Once the live conductor (Brown) is terminated I normally fit the cable grip around the flex to hold it in place ( fig 2 ), this is down to personal preference, you can of course fit it last if you prefer. Now measure the neutral conductor (Blue) to length, strip and connect (fig 3), and finally measure the earth conductor (Green / Yellow) to length and again strip and connect (fig 4).
Now fit the appropriate fuse to suit the appliance (see fuse ratings in plug tops post) and put the top back on securely (fig 5).