I would try to make adding tests as easy as possible. That is for every piece of code you write think to yourself: How would I test this. If in many cases the c

I would try to make adding tests as easy as possible. That is for every piece of code you write think to yourself: How would I test this. If in many cases the code only makes sense in the context of the whole application running this might be a sign of danger. Basically you thinking testing might slow you down is a sign this might be the case. For some problems it is way easier to write tests than to solve them correctly.