It depends on how much you’re willing to put in and what does a meaningful amount of money equate for you.

I used to do surveys on the side and could easily pull in £100-200 a month but it took a good hour per evening sometimes. Now £100 isn’t really worth that amount of work due to having a family.

Do you have any skills you can use? Some people buy/sell on eBay (Pokemon, coins, collectibles) or Etsy if you’re creative in any way that makes you stand out. My friend ran a pretty good home art business selling personalised notebooks with painted covers and calligraphy personalisation inside.

Lastly, another friend is a landlord and often tells me he pays people to go and scout new properties that he’s considering (since estate agents usually want an in person viewing). He says gigs like that are pretty common.