Ovals are a handy shape to know how to make but they can be tricky to learn, so I'm writing this to try to explain them a bit better.
The oval shape is used to make a piece that ends up longer than just a simple magic ring.
There is also a way to kind of turn a magic ring into an oval (which I'll also explain).
The more chains you make, the longer your oval shape will be. I'm just going to use chain 6 in my example because it's smaller & easier to practice.
1. Chain 6. Starting in the second chain from the hook: inc, sc 3, 3sc inc in the last chain.
Turn so you're working on the other side of the chain & sc in the next 4 chains.
You should end up with 12 sc in total.
The next round starts in the first sc from the last round. Sometimes a pattern will say to slip stitch to the first stitch & chain 1. This helps keep the oval more even, but it isn't always necessary depending on the pattern.
2. Inc, inc, 3 sc, inc x 3, 3 sc, inc (18)
3. (Sc, inc) x 2, 3 sc, (sc, inc) x 3, 4 sc, inc (24)
4. (2 sc, inc) x 2, 3 sc, (2 sc, inc) x 3, 5 sc, inc (30)
An oval shape can start with one increase (2 sc) in each end to create a shape that's long & flat. You'd repeat the same thing, but instead of using multiples of two, you'd use multiples of three.
When you increase in multiples of three at each end, the ends are more rounded.
You can also increase by 4 to make each end wider/a bit more square/rectangular.
Magic ring start
1. Magic ring 6 (6)
2. Inc x 6 (12)
3. Inc, inc, 3 sc, inc x 3, 3 sc, inc (18)
4. (Sc, inc) x 2, 3 sc, (sc, inc) x 3, 4 sc, inc (24)
5. (2 sc, inc) x 2, 3 sc, (2 sc, inc) x 3, 5 sc, inc (30)
You can see that the shape is slowly turning into an oval.
Continuing to repeat the pattern will make the ends of the oval larger, but the shape wont end up as narrow as the chain start.
I hope this tutorial was helpful.