great post shaz!!
i love challenges, maybe not always in the midst of the struggle, but at the beginning when i am planning and figuring it out and then when it's done or i complete certain portions of that job...i absolutely love it, the feeling of accomplishment is great, even if no one ever got to see it, just knowing i can is enough for me.
so to answer the question, i know when i see the job, if there is some component that i just can't do because of a tool i don't have, then i won't attempt it. usually every job i do has some sort of component that challenges me, awhile back i did my first angled hood with raised panels, then just recently i did my first raised panel hood with an arched bottom. it always seems like there is something. i am about to take on my first octagon shaped kitchen, i am very excited about that one.
so i guess there aren't many things i won't try at least once....so far i've been very lucky and have been able to complete them all with pleasing results. hopefully my luck continues.
chris