Place your stem cutting in your vessel with enough water to cover the node. The water level will drop due to evaporation, so you should add water every 3-5 days as needed. You can watch the roots develop if you have chosen a clear vessel for your cutting.
Add your cutting, and then mist the surface thoroughly daily (trying not to get the cutting). Twice a day if it's hot or dry. By 'mist' I mean properly wet the surface of the soil. Every week or so, stick your finger in the soil further down, and water it 'properly' if it's dry.
A typical misting frequency during sticking (Stage 1) and callusing (Stage 2) of vegetative cutting propagation is to initially mist for 5–8 seconds every 5–10 minutes over 24-hour period. After three to four days, reduce mist to 3–5 seconds every 10–20 minutes during the day, and less frequently at night.
Place cuttings in the small jars filled ½ to 2/3 with water. You can place several cuttings in one jar, but it's important that the jars or containers are smaller because cuttings release hormones into the water that will encourage rooting, and you don't want to dilute that in a large container with lots of water.
The basic principle behind applying mist to vegetative cuttings is simple. Without roots, cuttings cannot adequately replace the water lost to the environment due to evaporation and transpiration mainly. To aid them along the beginning of their life journey we must replace this water loss with water applications.
Warm growing medium temperatures accelerate cell division which leads to faster callusing, root initial development and subsequent root growth. It also speeds up the dry-down rate of the growing medium, which also helps encourage better rooting. The best way to warm the growing medium is through bottom heat.
Several cuttings may be placed together in one container. Be sure to add fresh water as needed until the cuttings are fully rooted. Rooting will generally occur in 3-4 weeks but some plants will take longer. When the roots are 1-2 inches long or longer the cutting is ready to be potted up.
Cuttings use energy to form new roots. If the cutting has leaves, most of the energy comes from photosynthesis. Expose these cuttings to bright light, but not direct sunlight, during the rooting period. If you use hardwood cuttings that have no leaves, the energy will come from reserves stored in the woody stem.
The reason cuttings rot is that over time, the oxygen level of the water drops unless it's moving or oxygen is added. Not only do plants need oxygen in order to grow roots (and, indeed everything else), but the bacteria that cause rotting thrive in low-oxygen environments.
Some plants will root in water, but cuttings will develop a better root system when rooted in a soil-less potting mix. Sand or perlite can also be used, especially for cuttings that need good drainage and may rot if kept too wet.
If you root your cutting in water, it develops roots that are best adapted to get what they need from water rather than from soil, Clark pointed out. If you move the plant immediately from water to soil, the plant may be stressed. Instead, add a small amount of soil to the water that you're using to root your cutting.
Place the cutting in a clean glass. Poor enough room temperature water to cover the nodes of the cutting. Change out the water every 3-5 days with fresh room temperature water. Wait and watch as your roots grow!
Should we allow the cuts to dry out a little before sticking them in medium? No - while herbaceous cuttings are less likely to rot, they also root faster than woody plants because they contain less lignin in their stems. Don't give them time to dry out.
Try to wait until at least 50% of the cuttings have good rooting before potting them up; however, for some hard-to-root species, you may be lucky with only 10% to 20% success.
Light provides the energy for callus formation and the subsequent generation of adventitious roots. At the same time, light increases plant temperature and accelerates the drying of leaves, which can quickly dehydrate cuttings. (Under LEDs, this would be less of an issue.)
Technically, you can transfer your cuttings to soil at any time. In fact, you can actually propagate directly into soil, however, it's much harder to do within your home. When you propagate in soil, you have to keep a good balance of soil moisture, air flow, and humidity.
The sooner you can get your cuttings into a more normal environment with air flow and no dome, the better off they'll be. After about a week, remove the dome and monitor your cuttings to see if they begin to wilt. If they do, they're not ready to go dome-less, so try again in 1-2 days.
Cuttings are very delicate and vulnerable so pests, disease, the wrong growing conditions, too much water or too little water can all cause them to fail.