Hi there,
My very first sale occurred the day that my shop opened - because my boyfriend was sweet enough to buy an item! I think that goes to illustrate the importance of getting your family and friends on board and supporting your shop both in terms of word-of-mouth promotion and even actual buyers.
After that sale, about a week later, I sold my first item to (gasp!) a stranger. According to my shop stats on the date of that sale, I was getting a lot of traffic from the Etsy Home & Living (good thing I tagged my items "hostess gift"), treasuries (promote promote!), and my profile (because I was liking other people's items). That goes to show the importance of anticipating relevant and frequently searched tags, using and participating in teams actively, and participating in the Etsy community at large.
One thing I wish I knew when I started was not to use search ads. I haven't used search ads in my shop since perhaps the first month I opened, and if you search terms related to my listings, most of my listings still receive pretty good search rankings (first page at least). So I wouldn't spend money on search ads unless you have the perfect, timely listing for say, an upcoming holiday.
While I am still a relatively new shop (almost 7 mo., hurray!) and I don't have too many sales, I am noticing that my sales are increasing month by month. The most important thing I attribute to this is...to "just keep swimming"! As long as you keep up your shop and just do *something*, you'll at least learn something and at best make a sale!