1. Create a server
2. Open console
3. sv_cheats 1
4. bind "mouse4" "hurtme -120"
5. bind "mouse5" "mp_restartgame 1"

Then you restart the game using your newly created bind. and then get a buff using mouse4/whatever button you choose to bind it to. Proceed to rollout as normal, then restart game when you want to go back to spawn.

start a local server ingame, turn sv_cheats on, bind a key to do the hurtme -3957625 command(any number really) and then type or bind a key to restart the round with mp_restartgame.

also use net_fakelag x, where x is the number of ping you will get divided by 2 (net_fakelag 25 - 50 ping)

my old teammate laz made a rollout script which i found pretty helpful
rollout.cfg
// Rollout scripts
// ???Laz

// Usage: 'exec rollout'

// Set up the server (These are for use in offline practice mode).
// Change 'net_fakelag' to whatever your ping normally is.
alias setupserver "mp_tournament 1; sv_allow_wait_command 1; sv_cheats 1; net_fakelag 40"

// All the stuff for rolling out.
// Change hurt me to whatever buff you want
// this will vary for pocket (-200 is probably a good bet), -180ish for demo
// Use more if you want to jump in setup
alias reroll "mp_restartgame 1; wait 1000; hurtme -180"

// Change the bind here
bind g reroll

// Exec the setup commands
setupserver

https://www.youtube.com/watch?v=vQbj1AswwiY
using all of the server commands, you may also want to consider the variations of rollouts.
*not all jumps in my video are optimal to mid*

i'm sure mr relyt will be very grateful for the advice you gave him almost two years after he asked

i just watched the granary rollouts you demonstrated, and i have to say, for one, they're very sloppy, slow, and you hit like every corner, and the left rollout was wrong to begin with.

making helpful videos is great but please know the rollouts before you make one

Something I use that I found incredibly useful for practicing rollouts/jumps in general is a offline teleport script. This is one I found off the jump forums, lots of other helpful stuff on there if you're looking to improve your jumps.

//Settings
sv_cheats 1
con_timestamp 0
con_logfile console.log

//Binds
bind F1 gotoPosition1
bind F2 gotoPosition2
bind F3 gotoPosition3
bind F4 gotoPosition4
bind F5 gotoPosition5
bind ALT +savePosition

//Code
alias +savePosition "bind F1 savePosition1; bind F2 savePosition2; bind F3 savePosition3; bind F4 savePosition4; bind F5 savePosition5"
alias -savePosition "bind F1 gotoPosition1; bind F2 gotoPosition2; bind F3 gotoPosition3; bind F4 gotoPosition4; bind F5 gotoPosition5"
alias resetLogfile "con_logfile console.log"
alias savePosition1 "con_logfile cfg/position1; getpos; resetLogfile;"
alias savePosition2 "con_logfile cfg/position2; getpos; resetLogfile;"
alias savePosition3 "con_logfile cfg/position3; getpos; resetLogfile;"
alias savePosition4 "con_logfile cfg/position4; getpos; resetLogfile;"
alias savePosition5 "con_logfile cfg/position5; getpos; resetLogfile;"
alias gotoPosition1 "exec position1.log"
alias gotoPosition2 "exec position2.log"
alias gotoPosition3 "exec position3.log"
alias gotoPosition4 "exec position4.log"
alias gotoPosition5 "exec position5.log"

from: http://tf2rj.com/forum/index.php?topic=422.0

The one I use is slightly different and less polished, though I have not tried this one myself it should work fine. I liked having a script like this because overall I find it easier to grind certain jumps versus doing the whole thing over and over. This one seems pretty cool because you could probably just set up practice areas and just go to them as you please. For example have one right next to spawn door on blands, one at the bottom of the stairs heading to dropdown and one at dropdown itself.

map cp_badlands
sv_cheats 1
net_fakelag to emulate online ping
bind x "mp_restartgame 1"
bind c "hurtme -185"

x to reset, c to buff, go nuts

mp_restartgame_immediate 1 for hardcore mode

Yep you actually need to add this to spaceman's script (#5) or else sometimes the buff gets given to you before you restart which fucks it all up
In case anyone wants to use that old script
Yeah

this and this map is very good and easy to practise your rollouts (and other jumps)
You don't need any binds for that, just download the map :]

I remade this granary rollout video differently. hopefully this is optimal enough.
https://www.youtube.com/watch?v=Fd5wAcD-BaU

no offense but i dont think some of those jumps are optimal, have a look a kaidus' rollout tutorials if you want to see how its done

ok so, they're better, but at second you cant do a crouch jump to shutter door and still jump, your hp will be way too low, might even die from fall damage

so left rollout is a regular sticky jump to shutter door, if you're going catwalk, it's a crouch jump to healthpack, then out to shutter door, and jump, you can't skip the healthpack

your "right rollout" is basically irrelevant and outdated, garage rollout is better from the left as well

also you have left and catwalk rollout labels mixed up in the video