Thinking about your next post can be stressful, but don't worry, we got you!
Here's a nice list of ideas for your next posts:
Your bedroom or desk

Take a picture of a corner of your bedroom or of your desk, add some extra details for a better result, e.g.: sunglasses, a pillow, pen & paper, a book... This might also be a nice excuse to tidy your room a bit.
Start from the caption
First, write the most awesome caption you can imagine. Then try to match it with a photo. Keep it simple and funny otherwise you won't be able to find the right photo.
The three way split

Post split in trhee are not just cool, they are very easy to create too. All you need is a long photo and the Photo splitter:
Photoshoot
Can't decide which of your 200 selfies/landscapes photos looks best? Post them all! Group all the shots in a single post so you don't bother anyone with multiple uploads.
Your followers will quickly slide them, so you can think of a cool transition from one face to another, like "Happy, Mildly smiling, Serious and Angry", or a progression of the sun setting at the horizon.
Regram your fans and followers
You don't always need to work super hard. Let the followers do the work for you: With the help of a Custom hashtag, tell your audience to post content that you will then regram on your profile.
What's in your bag?

Lay out all the items in your bag or purse on a flat surface, try to create a nice pattern (Arrange the items by color, shape, dimension...). You might also want to consider where to place the objects to avoid having your shadow covering them when you're taking the photo.
Use a filter
Start posting a photo as you normally would, and when it's time to choose a Filter, try different filters than usual. You can also customize them and arrange them as you prefer. Don't forget to press and hold on the photo, while using filters, to see the original colors and check that the filtered result doesn't look too unnatural.
A photo of you
Let's keep it simple: Share a beautiful smile, there's no better idea for a post!