First of all, so to speak, February 1st is not only Saint Brigit's Day but also Super Bowl 49 Sunday. So, have an Irish-flavored Super Bowl celebration at your house. Serve an Irish stew, during the pre-game shows, at some point during the day, and if green beer is already available, stock up plenty.
Your front door wreath should already have its Saint Brigit's cross and a bright green shamrock. These ought to be attached 1 week prior to the 1st of February. Ditto for your Wintertyde tree: Saint Brigit's cross, shamrock, and a football for Super Bowl 49.
February 2nd is a more sedate observance than February 1st in 2015. Two Wintertyde holidays fall on the 2nd: Candlemas and Groundhog Day.
Your wreath can take two ornaments at the same time the other go up: 1 week before February 1st. Check online for a groundhog ornament and a candle ornament. Both will take some time to find. Or consider making your own. You'll want 2 of each. One for the outdoor wreath and one for your Wintertyde tree. Make sure that your candle ornament does not feature holly or anything
related to Christmas. A tealight makes a good candle ornament because it's the right size. Be creative in coming up with something.
More info here:
Once these 4 holidays have passed, shift into Saint Valentine's Day mode. Decorative items go up by February 3rd this year.