Which ones do you use?
I usually answer questions like this with: ALL the job sites. In my experience, you'll need a pretty large selection of sites to find enough freelance opportunities. Just pick a few sites and you won't have any opportunities to reach out to daily. It's unlikely that without daily sales activity you'll be able to find enough work.
Full disclosure, I run Folyo which does this sort of curation for you.
Looks interesting, I’ll check it out.
Sharon, if you are oriented to logo design, I would recommended Logoground - site with premade logos for sale. (https://www.logoground.com/) The most interested thing about the site is that there is no fee - you set your own price and get all amount when logo is sold. I am really satisfied with this site.
I have never tried Upwork, but I agree that you should be active on several sites like Behance, Dribbble, even Twitter. There are many sites like Fiverr, but summa summarum you can get better price for your design work if client finds you on Dribbble or Behance.
You can also go on Dribbble site to see where designers selling their goods. I know that you have asked for jobs, but a combination of passive and active income is also good to consider.
Veronika, thank you so much for your guidance and useful advice.