Propagation and cultivation of the plants in my webshop is easy

Just follow the guidelines below

Ceropegia

When rooting Ceropegia cuttings it is better to use a 2-node cutting, because one node can then be used for the roots and the other one for the shoots. Ceropegias require warmth during rooting (20-25°C.). Do not try to root them in water; they will probably rot off, but put them straight into the soil. If your cuttings arrive and look extremely dried out, you can put them in water (with a bit of added sugar) for no more than 24 hours; then put them in the soil. The easiest medium to get hold of is a mixture of peat and sand. Make sure water can drain away easily as they do not like wet feet. If necessary, you can add some perlite. The higher the temperatures, the moister they can be kept.
After a few months, you can start feeding them once a week (only in the growing season) with a general fertilizer (20-20-20): one gram per liter.

Epiphyllium
Cuttings can be kept out of the soil for up to six months, but preferably shorter, so do not despair if your parcel takes a while to arrive; Epiphylliums are tough. They can be rooted in a mixture of peat and sand. Temperatures from 15°C. onwards for rooting; once rooted they can be kept at a minimum temperature of 10°C., but they will grow faster if kept warmer.
After a few months, you can start feeding them once a week (only in the growing season) with a general fertilizer (20-20-20): one gram per liter.

Hoya
When rooting Hoya cuttings it is better to use a 2-node cutting, because one node can then be used for the roots and the other one for the shoots. Hoyas require warmth during rooting (20-25°C.) and also like bottom heat. It is best to put them under plastic until they have rooted to ensure a moist environment. Keep them in a shaded area as Hoya cuttings do not like full sun. Do not try to root them in water; they will probably rot off, but put them straight into the soil. If your cuttings arrive and look extremely dried out, you can put them in water (with a bit of added sugar) for no more than 24 hours; then put them in the soil. They require very open soil for drainage; if you can get hold of it use orchid mixture, or mix your own peat, grit, leaves, sticks or other rough material. Bear in mind that in the wild, they grow in leaf litter in the trees. Make sure water can drain away easily as they do not like wet feet. If necessary, you can add some perlite. The higher the temperatures, the moister they can be kept.
After a few months, you can start feeding them with a general fertilizer (20-20-20): one gram per liter. The higher the temperature you keep them in, the more often you can feed them; feeding depends on rate of growth, so if you keep them cooler in winter, do not feed until temperatures have risen again in spring.

Impatiens
Impatiens cuttings will arive in a sealed plastic bag. Plant them as soon as possible in moist soil. Do not root them in water, because they will then grow water roots which are of no use in the soil. So if you later transplant them into soil, they will have to make roots all over again. If your cuttings arrive and look extremely dried out, you can put them in water (with a bit of added sugar) for no more than 24 hours; then put them in the soil. Even if they look 'dead', they are not necessarily past salvaging, so always pot them up to see if they will recover! They need to be rooted under plastic, in a shaded area at about 15-20°C. It takes about 3-4 weeks before roots appear. They do not need bottom heat. Impatiens need quite a bit of water and do not like drying out completely. They do very well in a general soil/compost mixture.
After a few months, you can start feeding them once a week (only in the growing season) with a general fertilizer (20-20-20): one gram per liter.

Rhipsalis
They can be rooted and grown much the same as Epiphylliums. The only exception is that they like a slightly higher temperature in winter (15-20°C.).

Stapelia
Stapelias like a higher temperature than the sorts mentioned above, preferably 20-25°C at all times. Rooting is quite easy in a mixture of peat and sand with bottom heat. They can be kept at lower temperatures once they have rooted, but then they are more likely to rot off, so it is safer to keep them warm. If you cannot keep the high temperatures in winter, keep them as dry as possible. A number of species (for example: Stapelia variegata, Stapelia hirsuta, Huernia repens, Stapelianthus decaryi) can take temperatures as low as 5°C, but only when kept kept very, very dry.
After a few months, you can start feeding them once a week (only in the growing season) with a low nitrogen fertilizer (anything from 10-20-20 to 15-20-20): one gram per liter.