How to Start Meshing? Or Basic Tips About Meshing?
 

I want to start Meshing
Can anybody Help me how to start Meshing over Complex geometry?
For example?
How to chose element?
or
Some basic tips on Meshing?

What is your geometry? It depends. for example a complex geometry like airfoils and blades, because of high pressure gradient effects, you need to consider highly refined mesh close to the wall. Producing mesh over complex geometries manually is difficult. but there are couple of softwares you can work with.

Thanks

I want to meshing over NACA 4412 Airfoil. And major problem is how can i select element? Am i using tetrahedral, Hexahedral etc?

It is recommended to use quadrilateral elements all over the airfoil with a highly resolution near the wall to capture an accurate result. It also saves your time and memory and you can keep the Y+ down resolve the boundary layer all way to the walls. You can also use unstructured triangular elements far enough from airfoil if the whole geometry is very complex.
There is a sample mesh around a NACA65 blade attached here, maybe it can help.

best regards.

Thanks Sir