Amateur mistakes are all too easy to make, and can be very time-consuming, so here is a list of the top ten most common, and how to avoid them.

1. Have a spirit level to hand
Putting up a shelf should be a five-minute job, but saving time by not using a spirit level could cause all manner of problems later, when ornaments fall over or books slide off. Use a spirit level to establish a level edge (when the bubble sits exactly in the middle of the window), then use a pencil to draw a guideline to work by.

2. Use primers
Watermarks can be a pain to cover up. Painting over the stain with a water-based emulsion won't help; the stain will keep showing through, however many coats you use. Apply an oil-based primer paint or spray over the stain to seal it, and then you can cover it with any paint and colour you choose.

Cover waterstains with primer before painting

3. Think ahead
Bespoke panelling around a bath and toilet give a bathroom a clean finish, but bear in mind that, inevitably, there will be the odd leak, and you will need access to the pipes to fix them. It's easy to plan one removable panel or concealed door for this purpose, and this will give you a place to hide the spare toilet rolls and soap as well.

4. Avoid quick fixes
After wet weather, wooden doors become swollen and stick in the frame. Planing the wood is an instant fix, but be sure to paint over the exposed edges with an oil-based primer as well. If the wood is not sealed like this, it will continue to absorb moisture and swell up - leaving you to do the job all over again.

5. Don't scrimp on essentials
There's no point in buying expensive paintbrushes for one job, but steer clear of budget brushes. These have fewer bristles, which make an untidy finish, and they moult more than a mid-range brush, so you will be constantly picking bristles out of the paintwork. Synthetic brushes are fine for the DIYer, and they keep their shape, while natural bristles tend to splay out after use.

Protect carpets with masking tape when painting skirting boards

 6. Protect surfaces
Painting a skirting board can be a painstaking job as you try to keep the paint away from the carpet. The obvious solution is to pull back the carpet edge; this is not always practical, but spending five minutes fixing masking tape along the edge of the carpet will do the trick. If you are staining a wood skirting board, remember to protect the joining wall with tape too.

7. Support your shelves
When putting up shelves and pictures on a partition wall, you must locate the weight-bearing studwork behind the plaster for support, or screws and nails will come out under the slightest weight. These wooden posts, which are the backbone of the wall, may not always be where you want your nail to go, but in this case, you can always use cavity fixings, which anchor screws and nails into the plaster. These are available from most DIY stores and websites.

Check and then double check how much wallpaper you will need

8. Don't under-estimate materials
If you are wallpapering with a patterned design, you will need to take this into account when buying. If the repeat is much more than 55cm, you will need extra rolls, as there will be more waste when cutting the paper to join up the pattern. Make sure the rolls have matching batch- and shade-numbers, and remember that off-the-shelf wallpaper can usually be returned if unopened, but most mail-order companies do not accept returns.

9. Prepare thoroughly
Always clean walls and skirting boards before you start painting, vacuuming rather than sweeping, as any dust floating around will stick to wet paint and ruin your hard work. Keep dust sheets down until you are sure all the paint has dried, especially gloss, but be careful with sheets on wooden floors, as they will slide around and can be dangerous.

10. Less is more
Lastly, whether it's wood, wallpaper or carpet, check and double-check every measurement before making a cut - you can always take more off, but if you cut too short you have wasted your time, your material and, most importantly, your money.

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