The main themes are harvest and the Sun God Lugh (pronounced "Loo"). At Lammas he's slain and will be resurrected at Yule in the form of the new God (much like the Christian Jesus). Some people make a Corn King to represent Lugh.
Here are a few links with more info about Lammas aka Lughnasadh (also click on Lammas at the start of the post to read more about it):
Since Lammas is the first of the 3 harvest festivals (the other two are Madron/Mabon and Samhain) baking, bread and corn are big parts of this festival. Don't feel you have to bake though; it's only one way to celebrate. :) You might like to make your own Corn King/dolly. Here's a link with instructions: http://www.edenproject.com/learn/for-everyone/how-to-make-a-corn-dolly
I normally make gingerbread. However the first year I celebrated (August 2010) I made Cornish pasties and sweet pasties, inspired The Real Witches' Kitchen book by Kate West. I also happened to bake bread around that time, so I had it on Lammas. I think was reading my old magic books and that's what inspired me to start celebrating the sabbats.
I actually made two lots of bread that year (with my family's help), the first one was part of a bread spell from Marina Baker's book Spells for the Witch in You but it didn't rise properly! So we tried again on 31st July, using a recipe from a flour packet. (I realised later that this is when some people celebrate Lammas). We made a loaf and our own rolls. It was more successful this time! lol. I haven't made bread for Lammas since then; I usually make gingerbread and sometime Cornish pasties. I'm going to try this year though, so let's see how it comes out!
I'm using a recipe from a magazine that I've had saved for ages. I need to check which magazine it is but for now here's a recipe from Moody Moons blog: https://moodymoons.com/2015/07/31/baking-the-lammas-bread/
Also if you can't eat gluten then here's a gluten free recipe: https://www.thoughtco.com/celebrating-lammas-gluten-free-2562178
The picture above is of yoghurt/yogurt cake that I made recently. It's like a loaf cake rather than bread but you may prefer to try making something like this, rather than baking bread. It's quite easy to make. The recipe is an old one from Somerfield magazine and that supermarket doesn't exist anymore, but here's a similar recipe: http://www.thelondoner.me/2016/03/french-yogurt-cake-easiest-cake-world.html
If you'd like to make Cornish style pasties (I don't think you're really supposed to call them Cornish pasties unless they've actually been made in Cornwall!) or gingerbread check out this post: http://livingseasonal.blogspot.co.uk/2014/08/lammas.html
Or if you want a couple more alternatives try quick dinner bread or no-yeast dinner rolls:
Now here are some posts with more celebration ideas:
I'm already doing No. 2 in Tess' 5 Little Ways to Celebrate Lughasadh post (Bake something and eat it). She also suggests lighting a green candle (No. 5). I have an orange candle that I bought when I got the yellow one I lit at Litha and I may light that this Lammas. In the book Pagan in the City by Cassandra Eason she suggests lighting an orange candle. The colours of this festival are gold, orange, yellow, red and green, so if you feel inclined to light a candle to celebrate then pick whichever you feel drawn to. (White can also stand in for any colour; you could add a coloured ribbon or just light a white one). :) I'm going to do Tess' affirmation for gratitude and self love as well.
As I mentioned before, some years I've made a Cornish pasty/Cornish style pasty and Michaela from Penniless Pagan's No 1. idea is to eat a pasty. Another one is to have a beer (No. 2). I'll probably have shandy this year. Some years I've had cider (last year I accidentally dropped the cider on the front doorstep after getting it out of a taxi and had to get some later!) but this year I think I'll have some shandy. And I like Moody Moons' idea for having a popcorn party (first on the list), although I probably won't do it this year.
This is a good time of year for learning about the Celtic God Lugh and the Goddesses Demeter and Ceres who are also grain goddesses. If you remember the Greek myth, Demeter is the mother of Persephone who went to live half the year with the God of the Underworld Hades and it was then that Demeter went into mourning and the land was plunged into winter. I wrote a story called The Goblin Prince which is party based on the Persephone myth (a girl going underground for so many months a year), you can read it here if you like: http://starsparklex.blogspot.co.uk/p/blog-page.html
Ceres is the Roman version of Demeter. You can read about Lugh, Demeter, Ceres and John Barleycorn, who is thought to be based on the Anglo Saxon figure Beowa, here: https://www.goddessandgreenman.co.uk/lammas
John Barleycorn is an English folk song. Listen to the song and learn more about the legend here: http://austinhackney.co.uk/2016/04/14/who-was-john-barleycorn-the-shocking-truth-of-an-ancient-mystery-uncovered/
The Scottish poet Robert Burns also wrote a balled version: http://www.robertburns.org/works/27.shtml
And here's a few more links:
This time of year is about abundance, so check out this good article from Demi of Rockstar Priestess about noticing and celebrating abundance: http://www.priestesstraining.com/grow-abundance-mother-goddess/
Think I'll try this. :)
Update 31/7/17: Here are a couple more posts with celebration ideas:
I just did Tess' affirmation. (The energy of sabbats can be felt for a couple of days either side of the official date. :)
Hope you're having a good summer so far! Summer is my favourite time of year and I enjoy going to the beach, so I'll finish off with a beach pic. I took this is mid July:
Ok, so that's it for now! Hope you found something in this post to inspire you. :) I'll do a post after Lammas about how I celebrated. Happy Lammas! :)
P.S. If you're in the Southern Hemisphere then it's your Imbolg/Imbolc. Have a good one! :)
If you celebrate Lammas/Lughnasadh what kind of things do you like to do?