Orchid leaves turned yellow and fell off?

[SophieOrchid]

Hi any advice on what I have done wrong with my orchid would be great.

I've had this orchid for around 1 year and it seemed like it was going well. It had already de flowered months ago and the older bottom leaves had fallen, which I read was normal. I was then told to snip the stems after the flowers had fallen to encourage new growth, I did this but nothing happened, the stems just turned brown. I went to ask the store owner (where I bought the orchid) if there could be something wrong? They told me to leave a small amount of water at the bottom of the pot as it likes the humidity. I did this making sure the water didn't touch the roots etc. Now all of the leaves have fallen and it's just a stump.. I am new to taking care of orchids so I have no clue what's happened and if I can do anything to save it? Thanks for any help.