I have to say that this is a technique that i learned from the guy of Manorhouse, it is not mine! (He is one of the less professional people i've ever met in this hobby , but he has a lot of experience

)
If you have a lake or a river near to you, i suggest the fine river sand instead of the grosser sea one!

(you're italian, right? i've seen you in the triplozero forum, if i'm not wrong!)