Two years ago we had Goldfinches nesting in the cherry tree in our garden.  Last year there were Dunnocks nesting in the hedge.  This year, prior to our holiday it looked like we were going to have Blue tits nesting in one of our nest boxes.
Since we returned from holiday however it seems as though the Blue tits have found a nest site elsewhere.  I see them nearly daily carrying bits of nesting material across the garden, occasionally stopping in our birch tree for a respite.  Either they were spoilt for choice or disturbed and decided not to use one of nesting boxes.
Now it would appear it is the turn of the Great tits.  They have been looking over the last couple of days at both one of the single boxes and also the sparrow "multi-box".  They keep looking, pecking around the box hole and going inside.  They aren't building, just viewing.  After all as anyone will tell you choosing a home is a big step!
I sometimes think our garden is a little small for nest boxes.  They are quite low, ideally above six feet is good, and our garden is quite enclosed.  We are though normally cat and magpie free (we have a dog who takes care of both of those aspects), and have excellent facilities, incl. all you can eat and drink buffet.
We'll see what happens.  In the meantime, anticipation is the order of the day.