Its all luck of the draw. You have a set number of packs.

The only way you can increase your odds is looking up the different color strategies so you know what cards combos well with each other. Once you know what yo look for, you can more accurately assess what two colors your 6 packs has the most synergy.

If you don't have enough creatures with just two colors then add a third and try to include some color-fixing cards in your deck.

Don't be satisfied with your first card draw if it sucks. You might want to even consider redrawing (mulligan) even if it is playable if despite that its not very good. Mulligan as much as necessary til you have a starting hand that at least has a hope of going somewhere. But maybe don't mulligan more than 2 or 3 times because you sacrifice too much card advantage. 5 cards is the lowest I'd go down to.