Depending on the level of your joinery skills, elaborate bird boxes can be made for your garden but that will be for you more than the birds who will inhabit them. What we have below are plans for a simple nesting box made from a single plank of wood, 150mm (6″) x 1580mm (62.2″) x 25mm (1″)
When you have the wood for your nesting box cut out, carefully nail or screw together the back, sides, base and front, then attach the roof with a flexible waterproof material so as the lid can be opened and the nesting box cleaned when the birds are finished with it. Hang the box in an area out of direct sunlight or in a partially shaded area so that the box doesn’t get too warm in the sun, the birds won’t build in it if they think it will overheat their precious eggs.
The size of hole in the front depends on the birds you want to attract, you can look this up on Google for various species. For Blue Tits and other small birds 25mm or 1″ should be ideal.