start with gettin' an infil an' see what he has ground wise.

then figure ur attackin' bonus in, an' then make sure when u attack that with ur attackin' bonus that u start with about 10% less droids than he has (includin' ur att bonus) an' try that once t' see how it looks.

also its always good t' have at least 4 or 5 planets t' use so if u flock up on one u still have more t' try with.

then simply hit an' hit an' hit (reducin' ur fleet a little each time u loose t' make sure u keep loosin')

an' its not neccessary t' win more than ye loose since ur usually ground runnin' fer someone else t' actually be hooverin' his planets t' take.

ur job is simply t' kill his droids down t' a point t' where th' guys u have hooverin' can win with what they sent.

Hope that helps.

PS when u do get good at it like Kagar says then you will be able to win more than you loose but still loose the planet, but for just starting out trying to do it, its best to be safe and not take the planet

or literally just shit on them