I admit, I always go a little berserk when it comes to party decor. I love dressing up the home for a party! Even the in-laws know that, and gamely chipped in to help the night before. My FIL even asked me about the theme, since we usually have a theme for each party.
This round, we were going for a construction themed party, but I opted to choose Lil J's favourite colours of green, yellow and blue. ("GEEEN! My favourite!" he always says.) I initially wanted to do large tissue pompoms, but baby J was sick during the days just before the party, so I didn't have time to make those. However, we managed to do up the usual crepe streamer backdrop, which has become a permanent feature at each party (you can see some of our other backdrops here and here). I love this, because crepe paper is so cheap, plus we get a burst of colours in the backdrop for group pictures. As usual, we looped the streamers on yarn, which we stuck up using masking tape. And we dressed it up further with balloons (my MIL and FIL helped me to pump these up with our bicycle pump), as well as a bunting which Junior J and I made using regular vanguard sheets plus poster paint (vanguard seriously is cheap but good!). One great find this year were the big balloons from Daiso: these go up to 28 cm across, have a nice sheen, and are really cheap (you get more than 10 per bag!).
Usually our party decor doesn't cost more than $10, and sometimes we don't even spend $5! (I can't really justify spending a lot on decor, since most of it gets tossed out.) However, this year I did splurge a little more on two things: flowers, which I bought from a florist the night before and arranged in two mason jars, as well as helium-filled balloons. Spotlight was having a sale on disposable helium tanks, so we bought one, as we figured the gas should last us for a few parties and would be cheaper than buying ready-filled balloons. So we filled up a bunch of balloons with helium and used the kids' vehicles to hold them down, and each kid got to bring home a balloon.
Oh, and of course I couldn't resist drawing on our chalkboard wall! Lil J was ecstatic on his birthday, when he woke up to find a birthday message on the wall, with all his favourite vehicles, and his face looking out of all of them!