I accidentally/ passively made 15$ this month so far. What are ways I can boost that?

So I used to have a website and it had some affiliate links on it. Plus I've been distributuing and linking people to them randomly. Apparently i've made a couple bucks and i thought it was pritty cool to have that. and VERY easy.

Because of that I was wondering, what can I do to make more money via affiliate marketing.

I have been imagining starting another website and sharing them there. However, im not sure how easy that is to do, My first site was based on my youtube channel. I dont do that anymore. So i would need to find a niche to promote products.

The 2 items that got me the most earnings where a Calvin and hobs box set, and a expensive pair of slippers. I would also imagine electronics is easy to sell but also hard because there are so many websites. I've honestly no clue what niche to focus on. Any tips?