Another excellent safety item that I recommend is a
bright-as-all-get-out strobe light. Use it during daylight hours! It really helps get the attention of the spaced out soccer moms fighting the kiddies in the back seat while balancing a Starbucks coffee in their lap all while holding a cel phone up to their head.
Like this one:
Here
I couldn't agree more, and $25 is a great price for a 1200 Lumen CREE T6 LED and LiPo battery back!
I was paying $40 for them and happy to pay it because I have seen first hand countless times a driver that would have crossed my path because they misjudged my speed slam on their brakes.
It only took that single broadsiding of a van when I was hauling donkey downhill without a light to never ride in daylight without a strobe again just like I never ride without a helmet. That helmet by the way was very damaged and had to be promptly replaced.
Along the same theme I urge you to make sure you have 2 good brakes or no doubt you will find out how good your helmet is first hand.
One last thing is forget tire slime even it is free, it is a messy pretty useless temporary 'after the fact' bandaid that simply will not last long.
If you use an HD tube and put a good liner between the tube and tire you can pretty much kiss flat tires good-bye.