First of all, its highly dependable on the situation or sport we’re talking about.
Of course, we can also try to look for similarities among these.
As a starting point, I believe the whole thing is a lot more difficult if your offense is flawed. In so far that:
1-your opponent has no respect
2-you lack the ability to unleash on the opponent at any moment, or make at least some advantage out of the evasive maneuver
3-your situation improves only for the moment, and/or gets worse overall
Under these conditions, you need to work on your offensive skillsets more then on your defensive ones.
regarding 1: this seems pretty clear. In a sport situation, this is often circumvented through starting easy and gradually upping the intensity of the sparring session. It’s also mostly a non issue with partners you know.
But train with new hotshots or in a new club full of assholes or fight with drunks and you’ll find some maneuvers will give you 0 points as nobody is judging you. The other may even get bolder, which is -in most cases- not good.
2:You need to understand how to turn the table, how to interrupt the opponent’s offense. Since this is easier said then done, at least analyze if you regularly move away from a situation you should be able to control differently, more effectively and if you just try to break away the “easy way”. If the opponent pressures you, is your evasion still effective? And it shouldn’t be flashy for it’s own sake (nobrainer).
3:If your moves are good but you still end up on your ass, perhaps you lack toughness? Is your maneuver entirely too defensive? Perhaps your moves are too elaborate?
An agressive opponent sometimes cannot be simply dodged, sometimes it is smarter to wear him out a little and to gradually seize the initiative.
Apart from specific drills, probably the best exercising is to fight with smaller (reach and weight), more unexpirienced guys. Don’t unleash here, control them with little offensive work and use clean evasive maneuvers applicable to your (standup) game.
There’s a good chance that you will find the clean “technicians” to be easier to control defensively.
edited for clarity