1) build something which could be interesting to other people 2) make threshold to test the product and post feedback low (e. g. GitHub) 3) promote it on HN,

1) build something which could be interesting to other people 2) make threshold to test the product and post feedback low (e. g. GitHub) 3) promote it on HN, reddit, producthunt... 4) people will test and some will report bugs / submit ideas etc.