...I noticed, that images of retro car details and tools isolated on white sell well.
But last year i did a lot of insect macro - will it sell? Also, are Ukrainian traditional county houses pictures worth uploading? And what about food macro - is it worth trying?...
Almost everything sells - the question is how many and what the competition is. If you can get an image approved and it sells once in a decade, I'd argue that isn't really very interesting. Something that sells a few times a day year round, or a seasonal image that does very well for the 3 months or so it's relevant might be much more useful.
Tools on white are easy for just about anyone to do, so even if the demand is good (and some tools are used as metaphors, opening up the market a bit), sales may be limited for you.
I don't really know about demand for Ukrainian locations and homes, but I'm guessing that tourism there is currently not a big market and the images don't apply well to any other market (i.e. they look distinctly Ukranian). So there may be a small-ish market. A search on SS for ukraine house
photos produced 33,000 results, so take a look at what's there to see if you have something to add. Agencies have been pushing for local content and things authentically of a certain place or culture, but the unspoken addendum to that is there needs to be demand from buyers for those cultures and places.
A search on SS for insect macro produced over 380k results (and probably many are not really macros, but still, it's a lot). Unless you have something really special, I'm not sure how you make a dent with so many already out there.
The good thing with insect macros or tools is that the images don't date quickly (unlike images of fashion or technology)