Two mistakes I made, and often see people do, when first using a moka pots is a) use an espresso grind on their coffee and b) to tamp down the coffee in the basket like you would when making espresso. Once I started to use a slightly coarser grind, halfway between espresso and pour over, and stopped tamping down the coffee (just tap it lightly to make it level is enough), I got much better results. Also remember that moka is not espresso. Too many people think they can replicate an espresso using a moka pot and just end up disappointed with the results.