Do you do Melacha Between Candle-Lighting and Sheki'ah?
One major difference between Sepharadim and Ashkenazim is whether lighting candles Friday night is an automatic acceptance of Shabbat or not.
Another major difference that is related to this is how to light candles - do we say the beracha before or after lighting candles?
Ashkenazim hold that the acceptance of Shabbat is immediately upon candle lighting - and not only that, but the acceptance occurs at the recitation of the Beracha. Therefore, Ashkenazic women who light candles may not do Melacha following candle-lighting. Also, Ashkenazic women light the candles, cover their eyes, and then recite the Beracha so as not to do the Melacha of lighting the candles when Shabbat has already been accepted upon reciting the Beracha.
Sepharadim hold that the acceptance of Shabbat is at Sheki'ah - not when the candles are lit. (I've read elsewhere that this is only if she lights at or around the normal time, but if she lights a lot earlier than the normal time, then she is showing that she accepts Shabbat earlier from her actions.) Therefore, Sepharadim may do Melacha after candle-lighting. Also, Sephardic women say the Beracha and then light candles, just like every other Birkat Hamitzvot, which are said עובר לעשייתן. (BTW, the Ben Ish Hai holds differently in this matter.)
However, Rav Ovadia Yosef says that it's "טוב" (good) for Sephardic women to be concerned about the other viewpoint, so women should make a verbal תנאי (stipulation) once a year that they are not accepting Shabbat upon the lighting of the candles.
Sources: here and here.
I've read that the ideal time for women to make this תנאי is Erev Rosh Hashana.
As with all halachic posts, ask your LOR for what you should do.