I am currently to create my own volatility smile for cryptocurrency options. I am basically reading the bids and offers and calculating the implied volatilities.
I now want to shape and parametrise my own volatility smile. What is a good way to do it? I tried the Corrado-Su Model, but I was not too happy about the results. Currently I use something simple:
$$\sigma(X) = \sigma_{ATM} \times (F/X)^{1-\beta}$$
where $X$ = Strike and $F$ = Underlying Price.
However, having only 1 parameter ($\beta$) to calibrate is a bit small.
Are there any other simple implementations to build a volatility smile?