What is the best way to add an indent to the side of a cylinder

Hi, i wouldn’t call myself a beginner on blender however I’m having a problem which i think would be pretty simple to solve.

I am creating a water bottle however the water bottle I’m creating has a indent in the side of it to make it easier to hold for the user, i don’t know what’s the best way of modelling this into the side of the cylinder.

It depends on what it actually is. You can really only see a faint line on the reference. If you really want to make it realistic, you should find a better view and find out how it actually looks.

If you don’t need to be precise, any way of making it is fine as long as it looks similar to your reference. I don’t see anything wrong with the one on your model. I see many forms and proportions not matching the reference in the details on the top though. You can find more reference for it quite easily

To be honest none of it matches at all when I consider form and size. Not a single feature…

Going to edit mode and either add an edge loop in the center of where you want that flat part to be or click on the verticies that’s near area where you wanted to be flat. Also make sure you’ve added some vertical edge loops on the adjacent sides of where the center of the flatpoint you’re wanting to add. Now go to the center verticies and delete it, and select the perimeter of that hole in add a looptool circle to it. Now adjust the verticies of that circle to get the shape that you want and add another edge loop around it and bring it closer loop you made with the loop tool to sharpen the edge