First of all you'll need to go to the games directory, this can be done by two diffrent methods. Either by navigting to the below directory:
"<Steam Install Location>\Steam\steamapps\common\Counter-Strike Global Offensive\csgo\cfg"
OR
With Steam open: click Library>Right Click on CS:GO>Click Properies>Click the Local Files Tab>Then Click Browse Local Files. Then you can navigate using the directory above.


Once there you'll have to make a new file called autoexec.cfg, the best way is to make a new notepad document, open it, then save it as "autoexec.cfg" with the file type selection box on "All files (*.*)"



Then open this blank document in notepad or notepad++ (recommend), then that's it, you have a blank autoexec.cfg file. You can now either fill it out yourself with a list of commands or use someones else's. You can copy mine below.

/////////////////////////////SENKA WOLF////////////////////////////////
// Updated 31/1/2016

////////////////////////////Out-game settings//////////////////////
///Used As a Reminder if I format
//Steam Startup Comandline//
// -high
// -threads 4(change to the number of core your CPU have)
// -novid
// -nojoy
// -tickrate 128
// -language bananagaming
// +exec autoexec.cfg

////////////////////////////////////////CMD/CONFIGS/////////////////////////////
// Primary Commands
con_enable "1" //Enables Console

// Crosshair Settings
cl_crosshair_drawoutline "0"
cl_crosshair_dynamic_maxdist_splitratio "0.400000"
cl_crosshair_dynamic_splitalpha_innermod "1"
cl_crosshair_dynamic_splitalpha_outermod "0.900000"
cl_crosshair_dynamic_splitdist "0.500000"
cl_crosshair_outlinethickness "1"
cl_crosshair_sniper_width "1"
cl_crosshairalpha "255"
cl_crosshaircolor "5"
cl_crosshaircolor_b "255"
cl_crosshaircolor_g "0"
cl_crosshaircolor_r "255"
cl_crosshairdot "1"
cl_crosshairgap "-3.500000"
cl_crosshairgap_useweaponvalue "0"
cl_crosshairscale "1000"
cl_crosshairsize "4.5"
cl_crosshairstyle "5"
cl_crosshairthickness "1"
cl_crosshairusealpha "1"
cl_fixedcrosshairgap "-10"

// Rates (Settings are optimized for best networking experience)
rate "128000" //Max bytes per second the host can receive data
cl_cmdrate "128" //Max number of command packets sent to server per second
cl_updaterate "128" //Number of packets per second you are requesting from the server
cl_interp_ratio "1" //Sets the interpolation amount (final amount is cl_interp_ratio / cl_updaterate)
cl_interp "0" //Sets the interpolation amount, always set this to 0
cl_lagcompensation "1" //Lag compensation helps by eliminating combat latency from client side view
cl_predict "1" //Skip waiting for server feedback and simulate client side movement in real-time
cl_predictweapons "1" //Skip waiting for server feedback and perform client side prediction of weapon effects

// FPS
fps_max "61" //FPS

//Video
mat_monitorgamma_tv_enabled "0" //Turn off TV Mode

//Sound
snd_mixahead "0.05" //Makes sound as instant as it can get, making it easier to hear small things

//Other
lobby_voice_chat_enabled "0" //Turns microphone off in lobby, really useful
mm_dedicated_search_maxping "80" //Maxping Search in Matchmaking
cl_autowepswitch "0" //Disables automatic switch to a more powerful weapon when its picked up

// Mouse
m_rawinput "1" //Enable Raw Input for perfect precision (Raw input is unavailable on OSX)
m_mouseaccel2 "0" //Disables windows mouse acceleration initial threshold, safety precaution
m_mouseaccel1 "0" //Disables windows mouse acceleration initial threshold, safety precaution
m_customaccel "0" //Custom mouse acceleration disabled

// Hud Modification
cl_hud_color "5" //Changes Hud to Red
cl_hud_playercount_showcount "0" //Shows player avatars instead of numbers left
hud_showtargetid "1" //Enables display of target names, important
cl_hud_bomb_under_radar "1" //Draws bomb under radar, convenient
cl_loadout_colorweaponnames "1" //Weapon names are colored in loadout to match their rarity, cool feature
cl_radar_always_centered "0" //Centers map instead of player in radar, important
cl_radar_scale "0.3" //Radar Map Scale Size, 0.3 is perfect on all maps
cl_hud_playercount_pos "1" //Puts player information in the bottom instead of top
cl_radar_icon_scale_min "0.8" //Sets the minimum player icon scale, this value feels good

//////BINDS//////
bind "ESCAPE" "cancelselect"
bind "`" "toggleconsole"

bind v "+voicerecord"
bind "TAB" "+showscores"
bind "SPACE" "+jump"
bind "," "buyammo1"
bind "." "buyammo2"
bind "0" "slot10"
bind "1" "slot1"
bind "2" "slot2"
bind "3" "slot3"
bind "4" "slot4"
bind "5" "slot5"
bind "6" "slot6"
bind "7" "slot7"
bind "8" "slot8"
bind "9" "slot9"
bind "a" "+moveleft"
bind "b" "buymenu"
bind "c" "radio3"
bind "d" "+moveright"
bind "e" "+use"
bind "f" "+lookatweapon"
bind "g" "drop"
//bind "i" "show_loadout_toggle"
unbind "i" //So don't accidentally enable hud fade, which is very annoying
bind "k" "+voicerecord"
bind "m" "teammenu"
bind "q" "lastinv"
bind "r" "+reload"
bind "s" "+back"
bind "u" "messagemode2"
bind "w" "+forward"
bind "x" "radio2"
bind "y" "messagemode"
bind "z" "radio1"
bind "CTRL" "+duck"
bind "SHIFT" "+speed"
bind "F3" "autobuy"
bind "F4" "rebuy"
bind "F5" "jpeg"
bind "F6" "save quick"
bind "F7" "load quick"
bind "F10" "quit prompt"
bind "MWHEELDOWN" "invnext"
bind "MWHEELUP" "invprev"
bind "MOUSE1" "+attack"
bind "MOUSE2" "+attack2"
bind "PAUSE" "pause"
bind "DEL" "mute"

host_writeconfig // write settings to config.cfg
echo ""
echo ""
echo "autoexec.cfg executed"
echo "Made By Senka Wolf"
echo "Last Updated: 31/1/16"
echo ""
echo ""
echo ""

After you have made your autoexec file you need to complete two more steps to ensure your file is run correctly and also not overwritten.

When in the same file directory as above you need to:
Right click the autoexec.cfg file>Properties>Tick the Read-only box>Click Apply




























This will stop CS:GO from overwritting the file and you losing all your codes! Make sure you untick the Read-only box when you want to edit it or you'll struggle yourself.

Open Steam:
Click Library>Right Click on CS:GO>Click Properies>Click Set Launch Options...

Now you'll get a box appear looking like the one below but with nothing in it. Just copy and paste "+exec autoexec.cfg" (Without the "") into that box and click Ok. This will ensure that the file will be run when CS:GO is opened.

Thanks for taking your time to take a look at my guide! Remember to comment below any questions or improvments I can make.

Have a good day!

- Senka Wolf