Study the chart and identify a route that you feel comfortable with considering airspace and danger/restricted areas as well as available altitude and terrain.
Think about whether you want to stay over land or would be happy to cross the Severn estuary.
Think about what options would be available if you were refused a zone crossing and what diversions might be available in case of poor weather.
Then plot the route as you were taught, identify suitable way points, think about what ATC services you will use and any navaids you might tune into and you should be ready to go.
You might want to go to Perranporth rather than Newquay as its cheaper.
Possible route might be: Newcastle to the Manchester low level corridor, then across the Shawbury MATZ (they'll give you service), break the journey at Shobdon then across to Merthyr and Porthcawl (talk to Cardiff even though outside their zone) then overhead Chivenor and on to Newquay.
Good luck!