Here are some ideas for celebrating Là Fhèill Brìghde, based on Scottish customs:

• On the day before the festival (i.e. January 31) clean and tidy your house, ready for Bride’s visit.
• Decorate the place with flowers that are appropriate for the time of year - such as primroses, snowdrops, daisies or dandelions (and remember folks, don't pick wild flowers...). Light lots of candles in the evening.
• Celebrate the feast of Bride on the eve of the festival with a slap up meal of your choice. Dairy-based foods are especially appropriate, in particular mashed potato served with a well of melted butter in the middle for dipping the mash into as it’s eaten. Invite people around to join in with the festivities. You can set a place at the table for Bride as well, and leave some of the food and drink as an offering to her. Milk, porridge, mash are particularly appropriate.
• After dinner, try making a leaba Bride (the bed of Bride - an oblong cradle usually made of straw) and dealbh Bride (icon of Bride), dressing and decorating them as elaborately and brightly as you like. These can be made of rushes and straw, or you can cheat and use modern materials or ready made items.

  Once the doll is made, go to the door and softly invite Bride in. This was traditionally done with several women present, one to take to doll to the door and one to invite her in. Assuming you’re on your own, you could adapt the traditional invitation to something like "Bride’s bed is ready. Let Bride come in, Bride is welcome. Come in and bring blessings upon this house." Then place the dealbh Bride in the cradle along with the slatag Bride - a wand of white wood such as birch or willow, with a few heartfelt words to Her.

• If you have a hearth, spread the ashes smoothly and carefully over it before you go to bed and leave it overnight to see if Bride leaves any sign of having visited. Marks from her wand are considered lucky, but a footprint is considered to be an especial blessing.
• Leave offerings outside to Bride, if possible, or take them outside as soon as possible.
• Make the bonnach Bride, serving with lots of butter, cheese and/or jam/jelly. Don’t forget to leave some as an offering, with milk or water as a libation (for example); any left over can be had for breakfast the next day.
• Juniper can be burnt at the hearth or altar in the evening (just before bed) if no ‘positive signs’ have been received of a visit overnight, to purify the house and propitiate her.

 See also: Entries tagged with Là Fhèill Brìghde

And for Irish customs:

• On the day before the festival (i.e. January 31) clean and tidy your house, ready for Bride’s visit.
• Decorate the place with flowers that are appropriate for the time of year - such as primroses, snowdrops, daisies or dandelions (but remember, folks, don't pick wild flowers). Light lots of candles in the evening.
• Celebrate the feast of Bride on the eve of the festival with a slap up meal of your choice. Dairy-based food are especially appropriate, in particular mashed potato and onions served with a well of melted butter in the middle for dipping the mash into as it’s eaten (traditionally everyone should be involved in the mashing). Lamb, bacon, sowans, apple cake, colcannon and dumplings are also appropriate. Invite people around to join in with the festivities. You can set a place at the table for Bride as well, and leave some of the food and drink as an offering to her. Milk, porridge, mash are particularly appropriate, and lots of beer can be drunk since she was renowned for brewing it herself.

  Since Bride was said to attend the meal as well, it was customary to invite her in before everyone sits down to eat.

• Make a brideog, using straw or a broom handle, for example. Alternatively, actual dolls can be used, dressed specially for the occasion. Decorate it as elaborately as you like and place with the offerings you make to her, saying an appropriate blessing.
• Leave items of clothing, ribbons or pieces of cloth outside for Bride to bless as she passes by, overnight. Water, salt, butter and even (adapting to a modern time) medicines, can be left out as well, for blessing. These can all be used to encourage healing, especially for problems associated with the head, as well as for childbirth and encouraging fertility. The older the brat Bride is, the greater its potency for healing is said to be.
• Offerings such as cake or bread and butter should be left out (on the window sill) to indicate that Bride is welcome to visit.
• After dinner, make the cros Bride and/or crios Bride to hang above the door for protection in the coming year. Leftover straw or rushes can be left to make a bed for Bride if she wishes to stay overnight.
• Try churning butter on Bride’s Day.
• Visit a well dedicated to Bride, early on the day, and collect some water to sprinkle about the house as a blessing, concentrating especially on the threshold.