I went to Le Touquet for the first time today. Dead easy.
Fill in a General Declaration form and fax that off to the Customs people, and then fill in a flight plan for the outbound/inbound journeys and fax those off. Give it an hour then activate your flight plan and off you go.
I routed BPK-LAM-DET-LYD-Cap Gris Nez-LFAT. I spoke to London Information most of the way who handed me off to Le Touquet at mid-channel. The RT is really quite easy, the navigation more so (just watch your VOR tuning and tracking). The controllers at LFAT today were English speaking and it was all clear and easy. Before speaking to LFAT Tower tune into the ATIS so you can get an idea of what's going on.
When you arrive you pop into the lovely little terminal there and book in, pay landing fees and so on. We then walked down into the town, pleasant walk, and had lunch followed by a wander around.
Main points learnt today were to check the weather thoroughly, it can change significantly along the route, and really study your flight planning. I'd also recommend not doing this trip unless you are comfortable operating without a horizon. There's really not allot to visually reference when crossing the channel.
With regards to the weather, there's a couple of terminals to the right of the arrivals room that let you stick your route in and will draw up METAR's/TAF's from all airfields along your route.
Anyway, it's a great flight and I'd thoroughly recommend it!
Guide to filling in a Flight Plan
French Crib Sheet by a fellow PPRuNer
French Flight Planning (Great tool)
LFAT Plate