Applying Plaster to a wall. The first coat of plaster can be applied to the wall in many methods, this is the easiest one - it both cleans the wall of trowel marks as you plaster and provides a methodical way to apply.
More information about this method are below the video.
Short video showing application of the 1st Coat
The trowel tends to leaves a mess when it is placed on and taken off the wall. The top border is first applied - to get you away from the ceiling, which will tend to leave a messy edge (the 'top line' on diagram above)
But this will begin to be smoothed out when section 2 is completed. The trowel is taken off when it has turned into the next section (section 3 above). So there is a mess left at the mid-line of section 2 and the top of section 3 - but there is a nice clean sweep in section 2 that is free of trowel marks. when section 3 is completed the mess left at the top is smoothed out as the trowel is turned into section 4. So the vertical section being worked on is free of trowel marks. This mess from taking your trowel off the wall is always pushed along the wall and into the next section.
The mess left at the mid-line is then smoothed away when the bottom section is completed (stage 13). The trowel will tend to leave a bit of a mess at the bottom of the wall but this does not matter as long as it is kept flat it can be covered with skirting.
If there is to be no skirting on the wall then the starting point will be right at the bottom of the wall and care should be taken to ensure the floor is swept clean to avoid picking grit up on your trowel and transferring it up the wall.
If the skirting is already on the wall then just a bit of care will need to be taken to keep it flat where the skirting meets the wall.
The benefit of applying plaster with this method is that at any given time you know exactly where you are on the wall. In the later stages it ensures you swiftly but thoroughly move across the wall and avoid the tendency to jump backwards and forwards. Once you've moved on - carry on and only complete each section to the standard needed for each stage - don't be tempted to overwork it too soon, as it will probably not be a good use of your time.
If you are left handed then the process described and shown in the video should be reversed - a left handed person will work from right to left.