To me, the biggest challenge is time management. Once you work that out, everything else falls into place. And as others have said, you just try to include them in your daily life.
What Abigail mentioned about being aware of what particular number works for you is also very important. Some people have a temperament for a large flock. Some only for one or two. I know that two works well for me. If ever I decided to further expand my flock, I think my absolute upper limit would be four. But that's just me knowing how many I could incorporate into my particular household without sacrificing quality of care.
Well said!
And in addition, it is important to factor into this where in this World one lives! Areas that are affected by more extreme weather, specific industrial complexes, earth tremors, wild fires, etc... that may /will require one to quickly 'move' away from danger. There are specific alerts /time lines that dictate what time limits one has to react within. The shorter the time limit, the lower the number of individuals in your home that can be quickly /safely be moved.
The longer it takes or the longer one waits to start to evacuate the greater the likelihood of being forced not to take your 'Pets' with you. Once the limited number of evacuated centers that will accept 'Pets' fill, Officials than 'STOP,' allowing People to evacuate with their 'Pets.'
Regarding the number of 'Pets' that a household can proper /safely care for its a very sticky issue. Whether 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, etc... There is no hard and fast method of determining when an individual /family looses control, until its to late. Thankfully, the vast majority of People self regulate. Having said that, there is always that segment that for any number of reasons loose control.
Any feeling of hesitation should be seen as a self-limiter! At that point, its time to just say NO!