Whole bunch succulents ? Must be a new species. A pic or two would be an ideal suggestion

Sorry its out of focus, but it shows how the plant is tipped over.

Soil isn't what I would use and mod podging them in same pot isn't my fancy either.

Soil is working fine for my other plants. What should I do to make them stand up better though?

Wait for someone who also uses the same soil as you

if you stick with those plants long enough you will see what he means about the soil. you will want better drainage. as for the tipped over plant. I cant tell what plant it is, but it looks like one of the succulents that grows long strings. they will all tip over eventually if that's the case.

What are the wrong elements of the soil? The tipped over plant was upright when I got it.

For succulents and cacti it is best to have them in a soil that dries out very quickly. Simplest mix that would work is a 50/50 cactus soil/perlite mix. If you can source the ingredients, the gritty mixes that are discussed in length on here are even better. If you do a little research on here on soil/mixes you'll find some great posts by tapla explaining soils and water retention.

Also, having all of those succulents together might not work long term. I'm not familiar with all of them and their requirements, but I have learned the tough thing with putting succulents together is you need to make sure they all have similar light/water requirements otherwise you end up sacrificing some plants in order to keep others alive .

If the one that fell down looks healthy, the plant could've just been too top heavy for the stem. If it looks unhealthy it could very well be a watering issue.

Putting several succulents with different growth rates will end up being an issue. The tipped over plant is some type of sedum, and it will grow pretty quickly into a long vine. The plant at the bottom/center of your photo will also do this, but on a much slower scale. At most, perhaps you could move the sedum to the edge of the pot so it can cascade over as it grows. It may not ever stand upright again, but if any of the leaves come off, you'll get little spouts that will be upright (until they grow too long, of course). The photo below is a pot of the stuff that was grown in one year, from two cuttings about 3-4 inches long.

Personally, I'd move the tall cactus more to the center, and the two clustery types (at 7:00 and 4:00 in your photo) toward the middle. They will spread out and fill in.