How to be an effective scrambler at speedcubing competitions
Scrambling is an important role at speedcubing competitions but is also one of the most demanding and does require competition experience, it is an absolute requirement that you are very familiar with the official notation for the event you are scrambling. If you are looking to become a good speedcuber then you should be scrambling with the notation during practice at home (yes - for all events, even 7x7x7).
The competitors will all put their cubes ontop of their scorecards, the delegate will then load up the 5 scrambles (+2 extras at the bottom), once the majority of the cubes are down and the delegates lets you start you should try to ensure the cubes are evenly distributed among the scramblers and begin taking the cubes and scorecards and start scrambling. Once you have scrambled the first cube, check to see if it matches the scramble on the right hand side of the screen, if it does then sign the scramble box and put it in a cube cover with the cube and leave it out for a runner to pick up, if it does not then solve the cube and try again (for 6x6x6, 7x7x7 and megaminx you may not have to scramble correctly at the discretion of the delegate), then repeat this for all the initial cubes. For extra efficiency consider having a stack of cube covers between your legs so you can just drop the cubes in and pull the cover out each time.
Once you have scrambled all the cubes, they will begin to be bought back solved by the runners, you should begin giving the second scrambles out, check on the scorecard to see what number scramble they need next, as things move on there is likely to be an imbalance on how many solves each competitor has done, you should try and keep it even so if someone is on solve 2 and another on solve 4 then scramble for the person on solve 2 first.