I think that's the basic ideas.
I'll try anyway.
1st: factors (genes) exist in pairs. During formation of gametes, they are separated from each other and 'crammed' into different gametes.
2nd: During meiosis, each member of the pair mentioned above can be randomly 'crammed' into the same gamete with either member of the other pairs. This is due to their dependence on 'preferring' which way to go. I try to animate it, there's no laws specifically on how they prefer things and stuff. It's totally random. And the results: it's like you put on blindfold and pull out a bunch of damn colourful balls, you cannot predict their combination and nor can you force them to go in the direction you make up.
Have fun. They are very easy to understand. Don't get frustrated.