Well glad to see that people have already jumped in - don't worry Moongold it's OK.
Martha Stewart is someone I'm not familiar with (she's not famous in the UK). So my thoughts come directly from her chart.
I tend to start from the element balance and this begs the question of planetary weighting in the rough calculation. I count '2' each for the Sun and Moon and one each for the rest. I also 'split' the points if a planet is in the final degree of a sign. I have experimented with leaving Uranus, Neptune and Pluto out of this calculation because they move so slowly but I now keep them in. There's also a case for giving additional emphasis to the chart ruler and the Sun's ruler, if you want to.
On my simple count I have 6 fire, and 1 Water. There's clearly strong assertive drives here, with the strong Fire showing, someone who may well be impulsive, has to be on the go doing things, ooptimistic and dynamic, but can overdo things and risks burn out. The lack of Water suggests that she might not trust her emotions or people who act from emotions or feelings - that is not to say there is no sympathy or empathy but that these are difficult to fit into an approach to life.
This element balance may be deleterious to health if the Fire drive is given its head - strong Water placements can indicate that the body can more easily cope with toxins. The drive to work can lead to health being ignored and if the body cannot get rid of the build up of toxins then there will be trouble. Strong exercise needs to be built into daily life to offset this tendency.
The house placements reinforce the element balance, most points in the Houses of Life and few points in the Houses of endings or soul. She has a Scorpio Ascendant (though the MC strengthens Fire) so things may not be quite as bad as with only one Water placement. Indeed with the Ascendant taken into consideration, Air becomes the weakest element - not nescessarily strong on ideas or relationships (though see the comment on the chart shape below). Perhaps a distrust of intellectuals, an inability to stand back and evaluate. The relative weakness of Water and Air will be one of the issues running through the analysis. Does the Scorpio Ascendant more than compensate for the weakness of Water or do we go by planets alone?
The modal placements are mainly Fixed for the planets and both Ascendant and MC are in Fixed signs. this person has the staying power to see things through. The drive from the Fire signs will usually result in success because of this staying power. There is also reasonable Mutable placements - she can adapt and change in order to see things through - but strangely enough she's a little below average as an initiator on placements alone.
Traditionally Mars rules the chart and she was also born during a Mars hour - What is more Mars is in the Aries, the sign of its rulership. Again drive, assertion and agression are strong. The Scorpio Ascendant gives a tenacity and finality to the drive whereas Aries would be more explosive but not quite as deadly in the long term.
Three planets stand out - Mars, as mentioned, the Sun in its own sign of Leo and conjunct the MC and the Moon which disposits everything else but Sun, Mars and Pluto. More about the Moon later.
Of the Planets only the Moon and Mars are below the horizon. This is a strongly Southern hemisphere balance with the Sun at its zenith. The southern hemisphere is the more outgoing extrovert side to the chart - this is an outgoing public person, who will gain their identity through interacting strongly with others. The balance to the West (7 out of 10) suggests someone whose is more relationship oriented than self oriented - she may well seek validation for views and ideas in sharing them with others rather than drawing them from within herself.
Chart shapes are always something of a subjective decision as we are trying to impose patterns on spreads. I would probably go for a bucket here, with the Moon as its handle. Given the importance of the Moon as a dispositor, and its position in the second - concerned with the material world, money, own finances, etc - the drives identified above are likely to have a strong flavour of meeting material needs (though obviously not simply this alone). The second house and the Moon may therefore be pivotal to the interpretation.
. I enjoyed doing this exercise and learned quite a bit.