It's difficult indeed to draw lines whilst flying - which is why our PA28 checklists have a 1:500 000 scale on the back and a nice blank laminated area to scribble upon!
Use a topless pen - preferably a chinagraph - to draw the 'radial' line, then look out. Then check the distance and write it down, look out again. Then plot distance along the radial on the map. If in IMC, amend 'look out' to read 'check instruments'.
Fixing position from an ad hoc VOR or VOR/DME in IMC is quite difficult if you need to draw lines on charts. Far, far better to have a pre-drawn chart with range and bearing rings from the most convenient VOR/DME beacon.
When I was in the RAF, I produced 'kneepad' sized maps for our University Air Squadron Summer Camps at RAF St Mawgan which had a nice clear Lands End VOR/DME overlay, so it was dead easy to check position above OVC cloud - read off digital range and bearing from the nav kit and check your kneepad map!
I fear that too many FIs think that the use of ADF etc is a prelude to the hours spent boring around (in both senses) whilst practising NDB holds. Whereas really it is a simple (but expensive to install!) piece of kit which can give you a useful back up to visual navigation.
But GPS is indeed the way ahead - if used correctly!