I'm trying to create a glow behind a logo like the one in this video http://www.bar-visuals.co.uk/showreel.html (the first logo) but I just can't seem to get it to work. could anyone shed some light on how to do it for me? Also I'm just curious as to how he has got the yellow flourishes to look so bright?
Just play with the parameters of the Glow effect ... particularly alpha channel or color channel, glow radius, glow intensity and blend mode. There is nothing about that glow that can't be easily done with the native AE Glow plugin so, just FYI, there are also a few third-party glow plugins out there that have additional controls.
About making the "yellow flourishes to look so bright", it seems it's just a mtter of selecting the right shade of yellow and probably applying Glow to it as well, although it would be with very different settings than the more diffused glow behind the whole thing.