I’ve used a vendor for my friend’s 30th, and they did gold, silver, and black arrangements that looked really elegant. They also set up a balloon arch for the cake table and ceiling fills for the lounge area. If you want ready ideas, check https://balloonbarae.com/adultbirthday They focus on themes suited for adult parties, from milestone birthdays to stylish dinners. You can customize with confetti balloons or even name prints to make it personal but not childish. Delivery and setup were punctual, and it transformed the space without looking overdone.