Elana Roth has provided 6 great tips (soft skills) for being an effective data scientist. Following is a quick summary of must have practical traits as suggested by Elana...
Excellent Communication Skills - A strong data scientist is someone who can clearly and fluently translate their technical findings to non-technical teams
Knows THE Data, Not Just About Data
Knows When to Stick to the Basics - Good data scientists know to head for the core metrics when starting a project, or trying to figure out an issue
Check her article to go through all the 6 points in detail.