This document discusses techniques for speeding up adding custom markers to Google Maps. It begins with background on markers and why adding them can be slow. It then presents four levels of optimization: 1) Using custom icons but blocking the UI thread; 2) Reusing bitmaps for the same data; 3) Caching both markers and bitmaps in an LRUCache and generating them on a background thread; 4) Further optimizing by limiting markers on the map and distributing data loading across the UI thread. Live demo source code is provided and there is a recap and Q&A section at the end.