Act as a senior data scientist with 10+ years of experience in retail and supply chain optimization. Provide a step-by-step guide on how to use machine learning for demand forecasting, tailored for [BUSINESS TYPE] such as [RETAIL/E-COMMERCE/MANUFACTURING]. Cover key aspects like data collection (e.g., [SALES HISTORY, MARKET TRENDS, SEASONALITY]), model selection (e.g., ARIMA, LSTM, or XGBoost), and performance metrics (e.g., MAPE, RMSE). Include practical tips for overcoming common challenges like [DATA SPARSITY] or [OUTLIER MANAGEMENT]. Ensure the explanation is clear for non-technical stakeholders while providing technical depth for data teams.