Crocheting A curved kind of shape

[crochet_7]

Hi! I have been planning to do a crochet project recently, and there's one shape that I was wondering was possible to make with crochet. The best I can describe it is the way a gravitational field with something in it (https://i.pinimg.com/474x/6d/24/2b/6d242b53ac2b38fd5f496572c57335ec.jpg). I want to make some kind of square with that kind of dip (though maybe not as large, and not pointed at the tip) in it, but I'm unsure of how to even approach doing that. Any tips? Thank you!

[bgs]

You would be doing something like this

https://amysastitchatatime.blogspot.com/2016/01/bowl-cozyhot-pad-free-crochet-pattern.html?m=1

[Granny Square]

I couldn't get the original link to work, but it led to some suggestions, like this one for a black hole.  On that same page, there's a similar one that looks like an hourglass, sort of, basically the same image doubled but the bottom half inverted from the top.

So the hot pad pattern would sort of work except you'd need to start with just a few stitches at the bottom instead, and increase in a similar was as the hotpad from that 'almost' point--that would make the 'tornado' shape.  For the hourglass shape, I'd make one tornado, turn it over, and work into the underside of the first round of stitches to extend the same shape in the other direction.

General crochet physics (easier than black hole physics I'm sure):  To make a flat circle in SC, you start with 6 SC at the center and increase by 6 each round.  To get that 'tornado' look, you'd want to increase at a much lesser rate than that; maybe don't increase at all for a few rows (this will make a tube), then throw in 1 increase, a few rows later of working without increasing, add another...but you don't want to put more than 6 otherwise it will just get wavy at the edge.