You should normally paint your walls and ceilings with emulsion, acrylic or water-based eggshell. Non-drip emulsion is also available in jelly or solid form, and this is particularly good for ceilings. Never stir non-drip paint, no matter how lumpy it looks. You'll cause the gel structure to break down, and the paint will lose its non-drip quality.
Ensure adequate ventilation by opening windows before applying paint products
Tricks of the trade
Paint in sequence
Do you need to paint your ceiling? If so, do it before painting the rest of the room, as you're bound to get some on the walls. Move on to the walls next, and finally the woodwork. It's a good idea to start painting by the window or light source, and then in bands away from and in parallel to it. If you want to take a break, try and do this when you reach the corner of a room - not in the middle of a wall.
Buying a large amount of paint can save you money, but only if you know how to store it properly. As paint deteriorates over time, it won't keep indefinitely - although solvent-based paints do have a longer storage life than water-based ones. If you only have a small quantity of paint, you can store it in an airtight jar. Choose a size that leaves as little air in the jar as possible, always label it with the code number, name and type of paint and note the room it was used in. When you store paint in the tin, you can stop a skin forming by turning it upside-down for a few seconds (first making sure that it's shut tightly) to 'seal' the lid with paint. Alternatively, you cut a round of foil to the size of the lid, and press it down onto the paint to get rid of any air.
Using a paint kettle
A large tin of paint may be more economical, but it's pretty cumbersome to work with. Professionals always decant paint into smaller containers known as 'kettles' which come in metal or plastic. As it takes a lot of white spirit to clean oil-based paint from a container, it's a good idea to use a disposable lining of aluminium foil. Just mould the foil into the kettle, using more than one layer if necessary to make sure it's fully leak-proof.
Recycling unused paint
Water-based paint is better for the environment than a solvent or oil-based product, but whatever you use, never pour unused paint down the drain as it can pollute waterways. Get in touch with your local authority to see if there are any paint recycling schemes in your area.
How to apply liquid emulsion with a brush
First, stir the paint and pour it into a paint kettle so it's about a third full. Then dip a 100mm - 125mm brush into the paint to cover about one-third of the bristle depth. Press the brush against the rim to get rid of the excess. But try not to scrape it on the edge, as you'll take off too much paint and create a build-up on the inside of the kettle.
Start at the top of the wall and brush on the paint with short, overlapping horizontal and vertical strokes. Work in panels of about one square metre at a time, and let each area merge into the next while the edge is still wet.
Work your way across the wall. It's a good idea to finish a complete wall before you take a break - you might notice a change of tone where you've stopped.
How to paint edges
Rollers and larger paint pads are really good for covering whole walls - but they can't reach the edges. So you'll need to finish these off with a brush or small paint pad (a process that's often called 'cutting in'). You can do this before or after the main painting, but you'll get the best finish by doing it before painting the main area.
Top tip - Wear protective clothing
Wear something like cotton overalls to protect your clothes when you're painting - but don't wear wool, because the fibres will stick to the paint. A mask will protect you from the paint fumes and if you're painting a ceiling it's a good idea to wear a cap or hat to stop your hair getting speckled.
Paint four or five overlapping strokes at right-angle to the edge to fill the gap between the edge and the new paint.
Paint parallel to the edge and go over your first brush strokes in a long, sweeping motion. Repeat this until you've painted the whole edge.
How to bead where colours meet
You can use masking tape to get a neat edge where different colours meet (at the junction of walls and ceiling, for example) or where other walls are a different colour. Professionals actually use a technique called beading. This isn't difficult - you just need a steady hand. Make sure that the other wall is dry before you start.
Load your brush with a little bit of paint. Turn it edge-on and press it flat against the wall, a short way from the edge, so the bristles are slightly splayed to create a bead of paint.
With a steady hand, draw the brush sideways or downwards along the surface. Gradually work right to the edge to give you a clearly-defined line between the colours.
How to use oil-based paint
Oil-based paint is slightly more difficult to use than water-based paint, and you'll need to put on an undercoat first. Use a 75mm brush and work in 300mm square areas, making sure you clean your brushes and any spillages with white spirit. Oil-based paint isn't really suitable for large areas like walls or ceilings.
Oil and solvent-based paints give off fumes that are harmful to your health and to the environment. Always make sure there's plenty of ventilation while you apply them and while they dry. Try not to use them on large areas like walls and ceilings.
Start by painting three vertical, parallel strips - leaving a space slightly narrower than the brush between them.
Blend the strips together by painting horizontally, without reloading the brush with paint. Then, with a brush that's nearly dry, make light vertical strokes over the painted area to give an even coating. Repeat the process on the area below, working the wet paint into the dry so the sections blend into each other.