Network coding (NC) has attracted tremendous attention from the research community due to its potential to significantly improve networks' throughput, delay, and energy performance as well as a means to simplify protocol design and naturally providing security support. The possibilities in code design have produced a large influx of new ideas and approaches to harness the power of NC. But, which of these designs are truly successful in practice? and which designs will not live up to their promised theoretical gains due to real-world constraints? Without attempting a comprehensive view of all practical pitfalls, this paper seeks to identify key ingredients to a successful design, critical and common limitations to most intra-session NC systems as well as promising techniques and ideas to guide future models and research problems grounded on practical concerns.