The original notes and sketches will be filed in a clearly marked wallet - see "Creating a new cave" - don't take them out until you are ready to scan them, and put them away again as soon as you have finished. They may never be referred to again, but ultimately they are the most valuable record of your survey and are kept for reference if there is ever a problem.
After typing in all the data in survex format , run aven (the GUI interface to survex) and print out a centre-line plan.
Take the printed centre lines and redraw the survey round it, working from the original sketches as if this was to be the final published survey. You can "invent" details like boulders in boulder-strewn passage, but otherwise, draw only what was recorded faithfully in the cave. If this makes your drawing look bad - record more next time! If things really are unclear, consider taking a copy of this drawing back into the cave to clarify it.
Drawing a cave is not easy but anyone can learn to do it. Read the brief Cave Mapping - Sketching the Detail" 5-page llustrated guide by Ken Grimes which makes everything clear.
Make sure the drawing clearly shows the point of connection to previous surveys (look at the relevant drawing in the old survey book to ensure the sketches match and you really have connected where you think). Make sure you note which Question Mark was addressed by this survey and show the location of any new question marks, with an estimate of quality and any difficulties which will be encountered (eg. if it is a climb, are bolts going to be needed ? If a dig, is it a few loose boulders or a crawl over mud?)
CUCC use a set of symbols pretty close to the standard ones promulgated by the BCRA, with occasional differences - such as large-enough boulders which are sketched to scale using the US symbol. The current state of standardisation for cave survey symbols (a useful guide to what we should be using where possible) has been documented by Häuselmann, Weidmann and Ruder (1996), but this is up for discussion in 1997. An alternative set of standards can be seen from the Australian Speleological Federation here.
Make sure that you draw both plan and elevation (the latter should be an extended section, rather than a projected elevation) for horizontal passage. For pitches, several plans at different levels may be easiest (rather like the cross sections at each survey station used in horizontal passage). Also projected elevations may be useful in addition to the extended section. But learning a good set of procedures for using survex is the way to go.
If you did all that properly, there should be very little left to do in the UK, unless you have volunteered to help with drawing up the final survey. (Fool!) However, it is as well to check that you have done all you can before BCRA conference, by reading the Back in the UK page.