Some basic facts about me: I'm 24 years old, working professional, renting. My ideal ERE date would be 30. My plan afterwords is to travel through India and southeast Asia, study yoga, and start a new life teaching yoga in eastern Europe or Norway.
Since ERE is still a rather long term goal for me I don't want to get too bogged down with the details. I'll just use my total liquid assets (no retirement accounts) and my spending over the last twelve months (as measured by financial tracking software) as key performance indicators to track my progress towards the 4% rule. With each update I'll consider current successes and challenges towards reaching my goal with a focus on continuous improvement. I don't expect to be extreme right away, but I want to keep moving in that direction!

Total liquid assets: $15900.47
Total annual spending: $21362.28
Progress towards ERE: 2.97%
Thoughts:

Acheivements: Business travel! I'm currently traveling 90+% which results in the vast majority of my expenses being covered by the company and mileage reimbursement. Last month I only spent $638.68! This is really helping me save money. After reviewing my finances and the ERE blogs, I realized that I was making some mistakes with my tax strategy that was really holding me back. For the past 18 months I've been maxing out a roth 401K which is really great for the future me (if he survives that long), but not so great for the 30 year old version of me that wants to bum around India and go surfing every day. Switched to the traditional 401K to lower my tax burden.
Challenges: Since I'm choosing to measure annual spending as a lagging indicator of the past twelve months, I really do not think this is representative of where I am now. I recently moved from the Bay Area to a much lower cost of living area. I've since lowered my car insurance, gotten rid of my cell phone, lowered my rent, and changed my attitude quite a bit. Moving into 2016, I expect to see some quick gains with the cost reduction improvements that I have made.
Goals: Continue to work on my yoga. Improve side hustle by learning tarot cards and giving readings at farmers markets (target market = middle aged women coming off their first divorce). Start side business (still working out the details).