Rooting cuttings of your favourite plants can help you get more plants for free. Here are some simple tips for beginners to get you started.
If in doubt I push odd cuttings into soil in a corner and hope. It is surprising what will root and grow.

Types of Cutting

• Soft wood cuttings are made from new shoots and tips that are soft and tender in spring. Dahlias, Chrysanthemums, Penstemon, Fuchsia, and Aubretia can be rooted this way
• Semi-ripe cuttings are taken mainly in summer when the young shoots have just started to turn brown and harden at the base. Pelargoniums, Forsythia, flowering currant Escallonia are just some plants that will root with this method
• Hard wood cuttings taken in autumn will take a bit longer to root but are used for roses, dogwood, black currants and many shrubs

General Tips

• The day before taking cuttings give the host plant a good watering.
• Choose strong healthy stems. Keep in a plastic bag whilst you collect other cuttings so they do not dry out.
• Remove the lower leaves and trim to just below a leaf joint.
• Place cuttings in a pot of cutting compost or soil with some sharp sand added.
• Keep humid and add bottom heat where possible.
• Adding grit to compost can stimulate roots

Tips for Soft Fleshed Plants eg. Pinks, Penstemon & Geraniums

• When cuttings are rooted pinch out the growing tip to get a bushy plant.
• Keep cuttings out of direct sunlight.
• Cuttings should  be taken in spring and summer.
• Cuttings should be 2″-5″ long depending on variety and available material.

Tips for Taking Hardwood Cuttings of Trees and Shrubs

• Cuttings taken between July and October for semi-hardwood cuttings, and between September and March for hardwood cuttings produce the best results.
• Cuttings take between two to twelve months to root well.
• Hardy plants should be rooted in containers outdoors or in cold greenhouses.
• Select  mature sections from the current growth at the base of the stem without  flowers, fruit or seed heads.
• Cuttings can be 5-15″ long with at least two leaf joints attached.
• How to take cuttings for big shrubs

Beginners Cutting Tips

• These general tips are about stem cuttings but you can also take cuttings from leaves, roots, and buds for some plants. Check links to specific plants for special requirements. You can root some plants by placing the bottom of the cutting in water.
• You can use a rooting hormone to encourage cuttings but I don’t and have tended to take more cuttings to compensate for failures.
• A heated propagator will be useful if you intend taking a lot of cuttings.
• Take enough cuttings so you do not have to worry if many of them fail to root. (But I bet you surprise yourself.)

Credits
Gooseberry cuttings by net_efekt CC BY-NC 2.0
Stevia cuttings after 18 days in water : bouturage de stevia après 18 jours by hardworkinghippy CC BY-SA 2.0