If someone's coming after you with thaumaturgy you've really got two hopes. One, that they haven't done their homework, or Two, you get to them first.
Thaumaturgy spells are effectively an attack of its power, weapon zero. The aim is to get an attack that will force a taken out where you've declared that DEAD will be the result. You've got to fill all of the targets consequences, fill their stress track and beat their defense skill and roll. Minor 2, moderate 4, serious 6, extreme 8 gives you 20 plus a 4 stress track and a say 4 skill and +4 best possible role. That's a 32 power spell to get most people (Shadow man's heart spell was more complete, targets 5 skill and an extra mild consequence and an extra point to ensure the stress track gets run down).
Hope One is that you have more an extra consequence, extra point of defense, a toughness power, a threshold or ward, or an aspect that you can tag. If they didn't go for vast overkill, and you have that extra moment of defense, you survive with only all your consequences filled in and your last box on your stress track filled, but you're not taken out. The other part of hope One is that they were lazy or economical in their spell and didn't prep an extra few aspects in 'just in case'.
It takes time to put together all the elements of a spell that big, and a pretty strong caster to pull it off ( thaumaturgy control of 5 or higher is a must as a -4 roll can and probably will happen in such a long casting), hopefully you either have enough allies to find out that someone is gunning for you or you don't have enemies that dangerous. This is where hope Two comes into play.
Against an enemy with unlimited time and resources and perfect magic control, kill or be killed is the only real option, much as Harry has done in at least 3 books.
Prevention is really the key, without a sample item to target with, thaumaturgy can't attack you. Even better a false sample item can cause an mistaken compel and result in the spell failing and thus backlashing with nasty results. Building a really powerful ward on your home is good prevention as the curse will degrade a lot when it hits it. Or you could just hide in the nevernever where earth bound spells don't reach unless aimed there.
As for simpler thaumaturgy like love spells or single aspect maneuver spells, getting them off after is much more achievable then resisting them. Though the above strategy still applies.