Decide what programs you want in your downline builder. Typically this will be one or more 'business opportunity' type programs, then a selection of your favorite traffic generation / promotion programs e.g. traffic exchanges, mailers, co-ops.
Next, create the 'instructions' for your downline to follow. This is your opportunity to teach them why they should join the various programs - and because they're following a system, a lot of them will do just as suggested.
All that remains is for you to promote your downline builder. You can modify and use our suggested templates or create your own, totally custom promotion pages. Either way, your downlines will grow like crazy!