Drawing in scale in Layout

I will import an elevation or plan from Sketch-up to layout and set a scale.
For example, 3/4" = 1’-0"
If I forget a detail, maybe a divider, how can I draw in 3/4" scale without opening up sketch-up?
I can draw lines in full size, 1’ = 1’, but it’s time consuming to mentally convert the dimensions.
Also, is it possible to exactly pick a point in scale, for example 1/2" away from a selected line.

Thanks, John

Unfortunately LayOut drawing tools only use the full scale.


Ah, thanks for your reply.