1) What was your meditative experience before and leading up to 1st Path?Getting to equanimity, then sliding back (i.e. the sense of progress over many sits), into the dark night, and even to A&P. Then again up to equanimity... it felt like an out-of-balance wheel, with not quite enough momentum, almost turning a full revolution, but stopping and turning backwards. Leading up to 1st Path, I took Tarin's
Reformed Slacker's Guide to heart and resolved to sit and otherwise practice as much as I could. I made a sheet of paper with a 10x10 grid (100 days) to tick off each day as a motivator.
2) How would you describe your meditative style/technique which ultimately led to 1st Path [Goenka scanning, noting, choiceless awareness, etc., a combination of techniques, etc.]? Noting my behind off, alternating with diving into samatha jhana.
3) How many hours were you practicing a day when you finally achieved 1st Path? About two hours sitting, and noting whenever I was walking anywhere. Since I work at a computer, I set up a "typing break" software to remind me regularly to rest my wrists, and I used those short breaks as well. Eating mindfully. Taking showers mindfully (i.e. noting whenever I remembered to). In my lunch break, I took (and still take) walks outside, doing lazy walking meditation (not pacing back-and-forth, but noting as I walked and looked around).
4) Did you maintain continuity of practice throughout the day when you finally achieved 1st Path; meaning, did you maintain mindfulness throughout the day, how and when, etc.? See question 3.
5) What was your samatha vs vipassana balance when you finally achieved 1st Path [for example, did you do straight-up vipassana, did you do a combination of samatha and vipassana practices, did you achieve hard jhanas before starting vipassana, etc.]? See question 2.
6) What was your retreat experience before and leading up to 1st Path? I did a couple of self-led, 1-day home retreats, where I alternated sitting and walking meditation (1 hour each) during the day.
7) What was your biggest stumbling block along the way to 1st Path? How did you ultimately overcome this? I thought fruition was an experience. I was looking for strange experiences, donut-shaped doors and the like.
Fruitions are insight-producing, not experience-producing. (Duncan Barford's words - he's right!)
8) Besides Daniel's book MCToB, what texts, resources, etc., were truly useful for your practice and were instrumental in finally achieving 1st Path? Did you work with any meditation teachers?I read the Sutta Pitaka (the four major nikayas, plus a lot of the Kuddhaka Nikaya) cover-to-cover in German translation.
Another resource that was very inspiring to me was
The Baptists Head, a website by Alan Chapman and Duncan Barford, where they recorded their experiences with the enlightenment process from the point of view of the Western Mystery Tradition. I found it very encouraging to see how they "independently reproduced" so many of the results described in MCTB. I also contacted Duncan and exchanged messages with him, "good spiritual friend" style.
Tarin's Reformed Slacker's Guide (linked above) was very useful to me.
He also coached me during the weeks before stream entry.
I listened to Dhamma podcasts and audiobooks a lot - I have a commute of about 40min each way.
Jed McKenna's books were very inspirational - to me, they were like MCTB with only the "lightning bolt" chapters.
I briefly worked with Kenneth Folk, a year or so before entering the stream. He gave me advice on visual meditation objects, and I hit 4th jhana during that time. That was before he set up as a professional meditation teacher.
As a child, I received a bit of teaching from my mother's meditation teacher. I don't know what tradition she worked in, but it was basically a technique of Progressive Muscle Relaxation and then a guided visualization. Just a few sessions.
9) What do you most wish you'd known when you were working to achieve 1st Path that you know now?That's kind of tricky, because who knows what would have happened? What worked for me, worked, after all.
The big intellectual "oh my!" moments were when Duncan told me about the insight-producing fruitions, and when Tarin asked me to investigate the sensations making up the sense of space during meditation in equanimity.
10) What is your best piece of advice to pre-1st Path practitioners?Just one?

find good "spiritual" friends with whom you can share your practice.
Some more good ones: practice a lot, don't underestimate off-cushion mindfulness. Study the maps, and see how the descriptions match your experience (
not the other way around!). Set up a resolve prior to each meditation ("may I reach X stage/state"), evaluate after each sit. Don't confuse content (such as weird experiences like the three doors) with insight.
Oh, and if you can manage to spend some time with someone you consider enlightened, do so! I don't believe in "transmission", but there's that effect on the mind when you see how ordinary enlightened people are, how they go to the bathroom and have unsophisticated political views and wear hipster glasses or unfashionable jeans, or mispronounce technical terms, or don't know the maps by heart, or don't believe in the gods, or talk a lot about Jesus... In short, how they have their idiosyncrasies and imperfections. That takes a lot of pressure off the self-improvement department.
Oh, and surrender. That doesn't mean "give up", it means "see it how it is, not how you want it to be". If it helps, surrender to a symbol such as the Buddha or a deity or saint or teacher. Or surrender to the present moment, or the universe, or the field of sensate experience.
Consider
how you would know that you had entered the stream. What if it happened at night while you were sleeping? How would you know? How would your SO know? Parents, colleagues, friends? (Maybe do this as a writing exercise now and then).
A toilet can be the seat of awakening. It's possible to use a remote, little used toilet stall at work or at school for sits. Lots of weird emotions and sensations come up. But be nice, and don't block the toilet for hours

Cheers,
Florian