When brainstorming marketing merch ideas, what comes to my mind first are items that are practical and represent your brand. Being raised by parents that had their own business, I've got the itch to hand on and sprinkle some of my ideas into this forum for you guys.
1. Custom Pens: Custom pens are some of the most wide spread marketing tools. I would recommend for you to get high-quality pens with your logo and brand colors on it. Usually people find them practical and actually use them, so they really help you spread your brands visibility.
2. Custom Keychains: I think keychains are like a portable billboard for your brand. If you choose high-quality materials you have the highest chance of your keychain being used for a long time.
3. Lanyards: Customizing landyards with your logo or even slogan is a great marketing merch idea. They are useful, visible and can even be handed out at events or conferences.
4. Reusable Shopping Bags or Tote Bags: With sustainability being one of the hottest topics today, you can't go wrong with eco-friendly reusable shopping bags or tote bags with your logo on it. They literally make a walking advertisement for your brand.
Just remember to make sure that your marketing merch items align with your brand identity and that they resonate with your target audience. If you have more marketing merch ideas, feel free to drop them in the comments below. Appreciate your input. :)