For me the most important part of making ADR work is getting a good performance from the actor. If the actor speaks too softly or doesn't scream when supposed to, it doesn't work no matter how close the character in sound matches the production sound. If you need to hit the actor to make him scream, then get someone to hit him! If you need to push and shake the actor then do it. Imperfections in the ADR make it sound more like the production sound.
I use a lot of reverb on all dialogue, production sound and ADR, to make it rounded and nice and to give a bit of stereophonic/5.1 life to the scene. The ADR normally gets a little more reverb than the production sound, typically a mono convolution reverb to match the early reflections you hear in the production sound.
I have no rules about EQ'ing other than just tweaking all bands until it matches the production sound. The production sound may have some pretty mean EQ'ing as well, especially with lavs hidden under clothes. You may want to tweak the production sound just before and after the ADR line to match the ADR, if they are too far apart in character.
If you have access to a big recording stage, then use it and try to match the microphones from the production sound. But often you are stuck in a small booth, and then you'll have to use the microphone that sounds best in that booth. There is no need to use a 416 or MKH60 in a small booth, it will only make you unhappy.