As nesting season approaches, many of us will be buying or building nestboxes to put up in our gardens, to encourage birds to set up home there.

"By putting up nestboxes, you are replacing habitat which is no longer there, replicating holes in trees, or nooks and crannies in old buildings, so it's making vital space for birds," says Helen Moffat of the RSPB (rspb.org.uk).

"It can also provide you with some great entertainment - a chance to watch the garden soap opera of the birds' comings and goings, with hopefully some cute fledglings taking their first flights at the end of it all."

As National Nestbox Week approaches, there are things gardeners can do to prompt birds into using nestboxes, which much depends on where they are sited and the types of nestboxes we install, whether it be an open-fronted box for robins, thrushes and flycatchers, a classic type with a hole for blue tits, or a tea chest for an owl.

Be an early bird

"The earlier you get them put up, the better. Some birds are already scouting out the best spots now," says Moffat. The main nesting season lasts from March to August.

Where should you site a nestbox?

Think about how high you put it - boxes for tits, sparrows or starlings should be fixed 2-4 metres up a tree or a wall, while swifts should be as high as possible, Moffat advises.

"Try not to put them too close together, as most species don't like near neighbours - it can be too much competition for food. Sparrows are the exception and will happily live in close proximity to other sparrows."

Ornithologist Dan Rouse, author of How To Attract Birds To Your Garden (DK), says: "Set them in a north-east direction to avoid strong winds coming into the hole, and you shouldn't get too much rain in there as well. Alternatively, put them where they have some shelter, then they can face in any direction. Tilt the box slightly forward so the rain can run off the roof."

Ensure there's a clear flight in too, and that it's away from places where cats or other predators could perch and get into it, Moffat adds.

Does the style of nestbox make a difference?

"Yes. Holed boxes should be around 4ft off the ground to deter cats and to provide the birds a clear flight path in and out of the box," says Rouse. "Open-fronted boxes can be anything from 3-7ft off the ground, popping them where there's some shelter.

"Robins love it if boxes are on a shed or hidden in some ivy, anything with extra camouflage," Rouse adds. "If you have trees, you can attach a box to them, as long as there's a clear flight path. Or you could put them on to a garden wall, a fence, or even your house itself or a balcony, if you tuck them inside a north or east-facing wall."

You can make your own boxes (there's advice on how to do this on the RSPB's website) but whether doing this or buying them, make sure of the quality of the item, Moffat notes: "The thickness of the wood ensures warmth for the birds and can be the difference in surviving a colder spring. A box which looks pretty but isn't water-tight is an ornament, not a home."

What about hiding them in trees or shrubs?

Rouse suggests: "You can buy roosting pockets, which are oval-shaped natural-looking baskets to put in the hedge for chaffinches or robins to nest in."

Does the nestbox colour make a difference?

"Birds aren't fussy about colours," adds Rouse, "although it depends on the species. For your typical garden bird like blue tits, great tits and house sparrows, they are not fussy at all, but the more advanced you get, if you want to attract say marsh tits or willow tits, they will need specialist covers put on them to resemble trees."

Where should you avoid planting a nestbox?

Rouse advises keeping nestboxes away from bird feeders: "A lot of people make the mistake of having their bird feeders a foot or two away from their nestbox. Birds defend their territories, so if you put a feeding station next to a nestbox, birds won't be inclined to use it as a territory because they know there are so many birds visiting."

Which types of bird prefer specific types of nestbox?

Moffat says: "Robins like an open-fronted box, while blue tits prefer a small entrance hole, which will keep other larger birds out. There are also specialised boxes for swifts, which mimic the kind of spaces they love under the eaves of old barns, cups for house martins and swallows and larger boxes if you have owls or birds of prey in your garden.

"It's also important if you already have boxes in your garden to make sure they're clean at the start of the nesting season, and ready for their next inhabitant."

Nestboxes with larger holes may attract starlings, a red list declining species, Rouse adds.

Should you put anything in the nestbox to attract birds?

"Leave it empty and when they discover it, they will mould it to their liking," says Rouse. "Some bird species will back off if they see there's already material in there."

National Nestbox Week runs from Feb 14-21. For details, visit nestboxweek.com