Are we the only parents who made a conscious decision NOT to use stair gates? Instead we "taught" ds to cope with them from an early age. This was on the advice of my best friend, who's a GP and mother of 4. Also, it would have been difficult to find a stair gate to fit the entrance to the main stairs - and which wouldn't have damaged the Vicorian plaster moulding.
In the early days, when ds started crawling (at about a year), we barricaded the top of the stairs (we live on the first floor) with something we could move easily for our own access. We then spent time with him "teaching" him to crawl down safely. Initially, we tried to encourage him to go down backwards on his front, but his preference was to bum shuffle down fowards, and after a while watching him, we were confident that he did so extremely cautiously and stopped trying to turn him around all the time.
We were more worried about the stairs to the attic floor, which are steeper and on a spiral - but he always coped with them fine - and we kept the door shut to them until we were confident about his ability.
Within a couple of months, we took the barricades away, and he was always fine. He learned to climb UP stairs at his great granny's in South Africa at 13 months.
Now, at 22 months, he is going up and down stairs standing up - he can do it on his own, using the wall for support, but prefers to hold my or dh's hand if we're there.
He shows a good awareness of stairs/steps - sitting down to shuffle forward and lever himself down if he thinks they are too steep, and he has never fallen down stairs.
Having said all of this - it did rebound on us once, when he got down the stairs, out the cat "flap" and round to the house next door without us knowing (see the thread on "lost child!" (my fault - I'd left the outside door open when leaving the house early).