Hello Liam,
I dry sail too, and tow my boat home for winter, so I raise and lower the mast at least once per season. This year it was twice each way, as I towed the boat to Bucklers Hard at Easter, rigged and de-rigged there and then brought her home before taking her to Plymouth later in the season. I think dry sailing is great if the boat is kept rigged and ready to go in a boat yard with a good slipway. The ability to tow to different places is also great but it is a fair bit of work, so the hassle:sailing ratio has to be carefully considered!
Raising and lowering the mast is fine and I often do it single-handed. As Jim highlighted, setting the lengths of the pole guys is necessary, otherwise the mast will slew to one side as it approaches horizontal (if lowering), or when it first lifts off (if raising). You can set the lengths if the mast is down but if you're starting with the mast up, you can only really judge it approximately.
However, if the jib pole/sprit does fall to one side, causing the mast to slew, it can be corrected by pulling on the appropriate cap shroud, which gives pretty good leverage. Or you can just keep one hand on the mast and shove it sideways as required (less leverage). Try not to let it slew sideways much or it will strain the tabernacle. It all seems rather daunting at first, as the mast looks very long, but remember that it's not very heavy, so there's little load on the lifting line (except when tensioning the rig to attach the forestay).
Once you've found the pole guy lengths, mark them with tape where the knots need to be tied. Alternatively, I've fitted rings on extra jib track sliders (which are also useful for sheet tweakers) and carbine hooks on the pole guys, so that they're just clipped on - much quicker and more accurate.
Control lowering by being careful to keep a turn of the line on the winch. I position myself (and anyone else) forward of the shrouds, to avoid a 'cheese-wire' situation should the mast fall for whatever reason!
There's one other tip that springs to mind but it relates to a separate post that I've just seen, so I'll reply to that. Apologies for not replying to your question sooner. Have lots of fun with your new boat.
Anthony Russell
235/02 Sea Wyche