Fitted Kitchen Scale Drawing ... Step 1.
Forget trying to learn all this scale drawing stuff, go out to a decent stationers and buy a pad of 5mm squared paper, or buy some ... [HERE]
Why? ... because in simple terms each square on the pad represents a 100mm dimension. (when comparing against a scale of 1:20)
So, when you come to draw your plan outline to scale you just have to count up the squares ... now how easy is that!
So in other words, if one wall is 3000mm long - you draw a line that is 30 squares long.
Or if a wall is 2450mm long - you draw a line 24.5 squares long
See example below:

Now when have drawn your outline - see how easy it is to continue in Step 2
1:20 Scale Drawing made easy ... | Step 1 | Step 2 | Step 3 |
Or, if you can't be bothered anymore, get a free design ... [HERE]