Matty - Most who look in the mirror and don't see much thickness (especially from certain angles) simply need to wait for progress. Decent mass gains usually fixes this like C_C and A_B said (provided you aren't neglecting body parts like KB said).
Often the type of person who'll complain about this are the type who'll maintain the same weight month after month. So if this is you, make sure you are moving forward in some direction. For example, don't try to be getting a ripped 6 pack while building muscle. If you want to get big, eat for it. If you want to lean up, eat for it and don't expect muscle gains.
No need for anything special when the whole body simply needs work. Your routine should be mostly basic movements with some isolation in there too (not the other way around). Don't be the person who doesn't even do the basics with good form/progression and ends up doing every exercise under the sun to try and compensate. A typical example of this is where lifters (even advanced ones) will do "everything" for their hamstrings (leg curls etc), yet don't even do something simple like stiff legged deadlifts which hits the main bulk of the hamstrings (especially the part nearest the knees).