In the northern hemisphere it is celebrated the 1st of August whilst in the southern hemisphere we celebrate on the 31st/1st of February.
This is the first of the Harvest celebrations and it signifies the beginning of the first harvest of bread (grain), first harvest of fruits (berries) and was seen as a time of friends, families, markets and Handfastings - which is a year & one day trail marriage of which either party could pull out with no questions asked.
Bonfires and dancing were a major part of these festivals and symbolic sacrifices of corn dolls and bread carvings were made to the God and Goddess...
To celebrate in a simple way, make a fresh loaf of bread or gather fresh fruits from the garden.
Then light a (controlled) fire in a pit and welcome the God and Goddess to your space.
When your ready place the fruits/bread etc into the fire and thank Lugh for all that is freely provided with your harvest and ask that he looks over the rest of your crop to ensure good harvest. Feel free to sit and enjoy the warmth and meditate.
When finish make sure fire is out...