Tips for riding in sand?

Having the right equipment is paramount.

Don't go against the grain.

Think light thoughts.

Before moving to another region I used to ride along a seafront promenade that's mostly smooth pavement but often has sand blown over it in spots.  Very treacherous.  The only things that work are what was already mentioned:  broad tyres at low pressure, make the center of gravity as low as possible and put weight on the rear wheel + no steering inputs and loose on the handlebars.  Take a leap of faith, go fast, if you slow down you'll dig in and it's game over.  Question is, can you live with the compromises of such a setup?  It works on the sandy patches but will bring no joy in terms of efficiency if 90% of your commute is on good tarmac.  With my 28 mm tyres nowadays, on the rare occasions where I see this type of sand carpet extending for more than a few feet, I dismount.

...tip : don't.

To be honest, sand has always been top of my bucket list

My regular commute includes a tarmac costal path that frequently has sand blown onto it from the beach adjacent to it, and I also ride now and then in Pembrey country park (including the odd CX and beach race) that that has very sandy 'soil' with lots of the trails being very sandy. My main tip is basically the same as L3gion above, and that is get as much of your weight over the back wheel as possible. That coupled with FULL POWER and keeping as straight as possible are the main things to focus on. Look ahead so that you can control your speed before hand, avoid braking on loose sand, and be subtle with your steering inputs. If you do need to turn on sand, be aware that you can easily find your front wheel turns tighter than anticipated and tends to tuck under you, especially if the sand is soft and deep. The worst one for me is a thin layer of sand on the tarmac path, as is acts like tiny ball bearings meaning very limited grip.

My advise would be to not ride in sand. Which rules out the New Forest, no great shame there. Flat and boring, and full of drivers that want to kill you.

Unfortunately it also means the Purbecks are mostly out too. Much more fun and interesting

If you absolutely have to ride in the sand, straight lines, minimal steering etc. But you will still probably fall off, so walk.

God I hate the new forest

Another handy tip, avoid the areas marked as "quick-sand" - they're not any faster.

Walk

Riding in loose sand is very difficult, it bogs you down instantly. Large volume with low pressure would be needed. Schwalbe do a 60mm wide G-One Speed explicitly for beach racing but that's niche.

As well as the obvious combo of tyres/pressures...something I do is try to keep my weight off the front end as I transition into patches of sand. Anything that overloads the limited grip on the front tyre can have you off easily if the front starts to wash out. The more I encourage the front to skim the surface the better, as handling rear wheel sliding/loss of traction is much easier and tends not to throw me off the bike or cause me to need to bail.

Dropping tyre pressure is your best bet.

And going down many gears.

And riding slowly.

I think it depends on whether the sand is wet or not. At Weston-super-Mare, the sand on the 'beach' is nearly always wet and it can support a lot of weight - it never gives in to pier pressure.