One hand gesture that I see quite often is the one shown to the right of this post. BEWARE! In many many countries showing the V sign with your fingernails pointing outwards means ‘up your bum’ or ‘fuck you’. So if you want to show ‘two’ or signal to someone to come towards you, be careful how you do it!
Here is an interesting article.
Notice also ‘the fig’ halfway down the page is the letter T in sign language but also equivalent to ‘fuck you’ in many languages.
When in doubt, keep those fingers to yourself!