Firstly you must always have cl_radaralpha 0 and also r_shadows 0 typed in console before playing other wise you will be sent to spectator.

Look for objects that dont look to be in the right spot, or look out of place.

You may power knife (right click) to not loose health. Fast knifing (left clicking) will result in you loosing almost 1/4 of your hp.

Using powerful and slow weapons is usually the way to go, although not always useful when an object is quiet small.

Use these tips and you'll soon be finding your self a better hide n seeker.

If anyone else would like you add more tips for newbies, your welcome.