All succulents (cacti are succulents too), will require as much light as possible, and just a little water (some may not need any).

What zone/general location are you in? Where are they going to spend the winter? Is there any natural light and how much? What kind of 'soil' are your plants in right now? - should be well draining, preferably not the peat.

If you are keeping them in cache pots (plastic pot in some kind of decorative container), make sure they are not too deep, the cacti in first photo is very deep. Put something in the bottom of that container to raise it up. The containers that your plants are potted in should have drainage holes. When you water, make sure they don't end up sitting in the water that may have collected in the cache pot.

Rina

Welcome to the funhouse that is the internet! I have run into the same problem lately as well. DO THIS, NO DONT DO THIS, back and forth and it can get tiring.

First thing to keep in mind, where is the person giving the advice from, is it in an environment similar to yours, growing conditions similar to yours? If yes then what they do will *likely* work for you (ensuring light, temps, and potting mediums are similar). For other people in a completely different climate or growing environment- their needs are likely different than yours so their growing advice, may or may not work for you.

My understanding is that cacti that come from places of very high altitudes and cold winters, need a cold rest and that often means low temps (anywhere from freezing to a few degrees above freezing) and high light if possible, but I've heard from many growers they'll put their cacti in the garage/basement/etc as long as it stays a bit above freezing.
Cacti that come from more humid, warmer, lower elevation places like Brazil need warmer winter growing conditions, things like melocactus and epiphytic cacti for example.

The haworthia and seedlings are the only two I think would need slightly warmer temps, the rest would probably be okay being pushed into dormancy, low light, for the winter. I am not an expert by any means, but just my two cents!

Thanks for the advice!

I live in Central Europe and the winter here is quite long (about 4 months) and we don't get that much light. I was thinking about puting the ones that still need light on a south-facing windowsill, so they get as much as they can and the rest of them to the garage, but they wouldn't get any light there. Would they mind not getting any light at all?

I'm using a cactus soil mix with some extra bark, but the plant on the first picture is new, so it's still in the soil I've bought it with. I'm going to repot it soon and also put something underneath the container, as you said.

Adela

Yes, they will mind not getting any light at all. Succulents really need light. Could you possibly get some supplemental lights? I am in Canada, and the winter is long, pretty cold and days short on natural light. I have fluorescent lights, some CFL light strips. It would help a lot if you can group all your succulents in one spot and get them extra light every day.

Another question I have is about temps - how warm is it going to be for them during the winter? You mentioned garage - is it warm enough? Some ppl have heated garage, I am not that lucky and my plants would freeze in the garage.

For the soil, it would help if you lighten it up. Many of us use mix with added grit, perlite, turface, some use scoria or pumice. There are more inorganic materials that can be used. Try not to use sand (as is sometimes recommended on the net) unless it is really coarse (usually sold as Horticultural sand). Fine particles will clog up the air space - plants need good air circulation too - and roots may 'suffocate'; the soil gets waterlogged, and the rot may happen. If you can't get anything else, get at least bag of perlite and add a lot of it into your potting soil (50%, even more of total volume would do). It may sound too much but if you get some lights and well draining soil, there will be great difference in your plants health.

Rina