Vida Ha presented best practices for storing and working with data in files for optimal Spark performance. Some key tips included choosing appropriate file sizes between 64 MB to 1 GB, using splittable compression formats like gzip and Snappy, enforcing schemas for structured formats like Parquet and Avro, and reusing Hadoop libraries to read various file formats. General tips involved controlling output file size through methods like coalesce and repartition, using sc.wholeTextFiles for non-splittable formats, and processing files individually by filename.