While working on UI intensive application on Visualforce, I extensively used  jQuery and Javascript Remoting to speed up my application response time on top of Visualforce, I designed bunch of methods that handles events from UI and generate dynamic query for backend. Having said this, some of the methods, I  would like to share with people out here which is little tricky but easy to implement.

How to retrive multi-values from a multi-picklist ?

So in case, you design multi-picklist and you would like retrieve those chosen value to generate dynamic query for remoting the controller to query Salesforce, here you can do it easily

Either you can use standard Visualforce Tag for multipicklist or HTML conventional select list 

You can implement this method easily as shown here to generate a formatted Query String to query Database