Ask a hundred succulent plant hobbyists about the best potting mix and you'll get 100 formulas...all the best on the planet! The reality is that most succulents are very tolerant of diversity - except when it comes to the big 'D', - no, not dirt, but drainage. The water must be able to penetrate and readily pass through the soil. Puddling and sogginess not allowed!
For those of us who grow en masse, this may be a major issue, forcing us to spend more time than we like trying to refine our soil to best suit the various plants we grow. But for most, a good basic growing medium is easily achieved by the addition of coarse builder's sand or horticultural pumice to a good commercial potting mix... about half commercial potting mix to half pumice (no fine stuff). The pumice is our preference, but isn't as readily available everywhere as it is here. As a substitute, I understand that some add baked clay (like used in hydroponics, not kitty litter).
As a genera rule, most desert succulents - especially cacti - prefer to be watered thoroughly and be allowed to dry out between waterings. In addition, desert cacti generally go dormant during the Winter, especially in colder climates, and during this time they don't need water. What this means varies from climate to climate, but in our area, if the plants are kept cool, we don't give them any water at all throughout the Winter. On the other hand, Jungle and tropical succulents (including cacti) don't like to go completely dry - any time of the year. And then there are special cases like Lithops! We'll send a special care sheet for these with each order.
Your choice! Clay pots dry out faster than plastic pots, and that must be taken into consideration. On the other hand, plastic pots are easier to clean and are more convenient and economical. But finally, the only requirement is an adequate drainage hole in the bottom. (I told you drainage was important! Emphasis on adequate! I've observed pots in the store with drainage holes the size of a pin head and others with the drainage hole glazed completely closed.) Other than this, the choice is up to you. In general, though, it's wise not to use a pot that is overly large for your plant. Even then, there are exceptions to every rule - except drainage!
We usually put it this way: bright, filtered light. Most succulents would prefer not to sit directly in the scorching sun...not that we have to worry much about that here in Western Oregon. (But even in this type of climate, use caution when moving them outside during the summer or you can expect some sunburn.)
Plants which are grown in pots need to receive fertilizer periodically to have healthy growth. We suggest use of a low nitrogen fertilizer and for ease of home use, we suggest a water soluble fertilizer every couple of waterings during the growing season. Over fertilization can result in "soft" and un-characteristic growth, which may look healthy to begin with, but can lead to rot and suseptability to other pests, so don't overdo it.
The most common insect pests are mealy bugs, scale and red spider mite. We can't recommend specific pesticides. Check the labels and observe all precautions. (Don't use Malathion on the Crassula family.) In addition, there are several non-chemical resources available. On small collections you have many options. And the best cure is healthy plants through proper temperatures, air circulation, good watering practices, and isolating new plants until you know they're free of pests. And, inspite of the above illustration, we don't have the European Brown Garden Snail!
And the most common cause of early death is rot. Cure: 'prevention' -- see above.
Most important: learn from your plants. Keep records of what you do and what works. In no time at all you'll be the expert.
Enjoy your plants!