Creating accurate sales forecasts requires various methods and tools, which generally involve defining the forecasting problem and objective, collecting and preparing data, choosing the right method and tool, building and testing a forecasting model, and generating and communicating the forecasts. Firstly, you need to define what you are trying to predict and why, as well as how far ahead you want to forecast. Secondly, collect reliable data from various sources and clean it. Thirdly, select the most suitable method and tool for your data, objective, and resources. Fourthly, build a mathematical or statistical model that represents the relationship between your sales and factors that affect it. Fifthly, generate forecasts for the future periods with your model and present them in an understandable way. Lastly, provide confidence intervals or error margins to show the uncertainty associated with your forecasts.