you asked for some tips and tricks, here they are:
-This symbol: (*) is used to mark commands which are only available if you use HLAE!
I personally use the inbuild recording system (commands: "startmovie <name>";"endmovie"). How ever, since valve patched this method you have to use a cvar unlocker to make it working again. Therefore I recommend HLAE (Half-Life Advanced Effects), which is completely free to use. Visit https://www.advancedfx.org
to download this extension.
To record with out lagging you need to use commands such as *"mirv_snd timescale 0", "host_timscale 0", *"mirv_fix playerAnimState 1". If the demo is still lagging jump back a round or two by using the demoui.
If you'd like to record your footage without any hud besides killfeed use the following commands: "crosshair 0"; "cl_draw_only_deathnotices 1".
In addition to that you can enhance the killfeed by using HLAE. It's to difficult to explain in a text and therefore I could create a tutorial if you'd like me to do so.
If you'd like to record your frags without any hud use "cl_drawhud 0". But remember: you wont see any scope overlays then...
Obviously you are going to change the framerate of your clips to create slowmotions and to sync your clips with music. Higher fps = higher quality and smoothness, aswell as bigger filesizes.
You can change the framerate with "host_framerate <value>".
E.g.: host_framerate 300 (my recommendation) -> recording 300 frames per second by using the inbuild recording system. You will get a bunch of .tga files which have to be converted to a video file.
You will need to use Virtualdub to create a videofile out of these pictures. Inside of Vdub you need to set the framerate to your <value>.
Afterwards you can use programs like After Effects / Vegas to edit your clips.
I personally use Vegas 15 to sync clips with music. Afterwards using After Effects to add colorcorrections and other effects.
If you and the community wish I could create a tutorial for everybody who is interested in learning how to record & edit cs:go clips.
I hope this will help you a bit.
Best of luck
*P.s.: Use common names to keep your profiles "secret".*