It is good advice not to crowd an ISTP since their number one aversion is a loss of freedom and personal choice.
After letting my ISTP husband know I was interested. I (an INTJ) actually avoided him for about a year. I entered his life again by calling him to ask about my car. (Natural troubleshooters--and they enjoy being helpful). Then it was two steps forward three steps back for about 6 months.
I made him gun shy with my directness. (Can we please clarify this? Are you actually asking me out on a date?) He still doesn't like answering a direct question and hates feeling pressured or like I am analyzing him and trying to figure him out. (He especially hates this personality stuff).
It didn't take long for the relationship to advance once he decided he was ready. He asked me to marry him 6 weeks after we began dating and we were married 3 months later. ISTPs are quick to get results once they know what they want.
I agree with INTJ mom's assessment. We enjoy each other's humor immensely and we have tremendously wonderful chemistry.

We love Adventure/Action/Sci-fi books and movies and we love working on our house together. We also enjoy discussing politics, God, science and technology. He doesn't think my constantly evolving theories are insane. We both like adventure such as hiking, diving and boating. We also enjoy just hanging out and not talking. We're comfortable reading next to each other or hanging out on the couch with our laptops.
We get into trouble because I like to plan things (like travel) far in adavance and he prefers to take things one day at a time. (Although he admits to liking the savings I get for booking flights, hotels, car rentals during the "off" season.)
He also doesn't like the fact that I am constantly trying to avoid trouble (I see where my kids are going with attitudes and behaviors and look for similar scenarios in the world around us to direct them to before they make the same mistakes). He prefers not to worry about tomorrows trouble "since each day has enough worries of its own." However I prefer to keep a lookout for troublesome trends and head them off at the pass.
He used to lecture me about the danger of "what ifs" of course he's seen over the past 8 years that my what ifs usually become truth so he's learning to trust my insight.
I also had to learn to trust his "gut" feelings (without explanations or evidence to back them) and not make him feel like I didn't trust him when I challenge his ideas. I have a tendency to come off like a know-it-all

but I really am just looking for all possible scenarios before making a decision.
Another trouble is that I am always reorganizing our house for maximum efficiency which he hates because he has to relearn where everything goes. Which leads to the final difficulty . . . when we do argue/fight he become intensely annoyed that I am almost always calmly trying to figure out why he's angry and solve it which only makes him even more angry because he feels like I am analzing him in a doctor/patient relationship rather than a wife/husband relationship.
I have had to learn to let him say what he needs to say with out commment and even let him walk out the door and disappear. I have learned that he always comes back with a compromise . . . and honestly we've only had 3 argument/fights in 8 years! Not bad really!
Over all we've had a wonderful mental/spiritual/phyiscial partnership. He likes someone who is as independent as he is and self-confident enough not to resent his forgetfulness of birthdays and anniversaries but who challenges him to keep learning. I appreciate someone who enjoys my logical reasoning and isn't trying to change me into someone more traditionally female. He also supports my dreams and believes in my abilities. We both appreciate a laid back life of mutual appreciation free from enforced obligations and stereotypical roles.
One of my characteristically longwinded answers. I apologize.