Rules:
1. If you die, restart the map. (I recommend doing this by respawning then as quickly as possible load the save)
2. Follow the mission objectives, otherwise just kill all the hostile NPCs (If you are unsure if all enemy NPCs are dead, a good enough test is to see if you are able to walk around in the open, in a central and open part of the map, without being shot)
3. Do not spawn anything, with the exception of the situation noted in the notes list below. (pretend the spawn menu doesn't exist)


The recommended settings for these saves are:
Damage multiplier: 5x
Enhanced Combine Soldiers: Disable Dodging/Rolling
Make a loadout that only contains weapon_empty_hands (empty hands swep) and set it as your loadout.


Notes:
If you do not spawn with a weapon in front of you in any map, then spawn yourself any weapon, with no extra ammo.