This question might have an inherent contradiction if you read it as small cap stocks with good long term history.
However if you are looking for promising stocks that might offer good future long term returns, then you can use any of the methods that have been documented by famous others like Warren Buffer, Peter Lynch, Benjamin Graham etc.
You can shortlist companies that have a good management, skin in the game, consistently deliver good return on equity, have low debt, are under valued compared to peers, are working on a ‘sun rise’ sector or strong ‘moats’ in established markets, etc.
My view is that you should get into stocks only if you have the time, skill and energy to research stocks. You will be competing with very smart professionals who spend 18 hours a day doing this.
Else, go for direct mutual funds (i.e., avoid regular plans that leak hidden commissions) to bankers/distributors. Choose a trusted advisory platform that helps you with honest advice, for a reasonable price.
