Are you aiming for daily sales?? Do you feel like you never know what to show? I have found it helpful to plan it out for the month and then I just use that same schedule each month. So that way I know I'm only doing a red sale once a month or a rhinestone sale once a month and I don't get confused on trying to remember if I did rings last week or not, etc.
When I have it planned out, it takes the pressure off! I just know what to show - and if I feel like mixing it up, I often switch days around, etc, but at least the schedule gives me a starting point.
Here is a list of ideas for flash sales, plus a blank monthly calendar and then the one I made. I have 2 sales every day, that's why there's two spots for each day, but adjust it to fit you - maybe you use the top box to plan your sale and the bottom box is what type of social media post you're going to do that day, etc.
Anyways, this has helped me so I thought I would pass it along in case anyone else finds it helpful.
UPDATE: I keep tweaking it, ha!, so here is my most recent version, I added an Alternative Themes section so that if there's a day when I'm not jiving with the schedule I can have a list of ideas to swap it out.