Crush them without adding anything, then freeze them in portions. If you add salt, garlic, oregano etc, these substances' natural taste will change over time. Freezing crushed (smashed?) tomatoes without anythign else added, leaves them without changing taste. I do it all the time.
I love pasta and usually have several portions of unflavoured crushed tomatos in the cellar's refrigerator. But always wiothout any salt,l spice, garlic, oil or pepper. If you add these and freeze it then, you will taste a difference to freshly created tomato sauce.
Also, don'T be afraid to consider to heat them (although this does change their taste a bit for sure). Tomatos are one of the very few vegetables that win in healthiness by heating them, the heat changes some chemical agents and make it better for the consumer. I do not have the details present and cannot explain it, but if you seek for it on the web, I'm sure you find it. It'S comparable to canned corn (maize?), which gets heated before getting canned to - and it wins in quality by that.
Strange, but true.
As a German food scientist put it: we lost those 40% of our intestine that enabled our ancestors or many animals and apes of today to digest those plant ingredients this part of the enteric was meant to digest, by externalising these 40% - and calling it our kitchen and our oven from then on. It is a myth that uncooked vegetarian food or wholefood corn is always better and richer, although I admit I feel for that myth myself for many years, too (which does not necessarily mean a conclusion that superfine flour is less unhealthy). But over the past two years I learned too many medical facts that simply forced me to change my understanding of wholefood and uncooked vegetarian food theory.
Some things remain to be unhealthy, though, like too much salt, too much sugar, too much red meat, too much fat.
Anyhow, freezing unrefined smahsed tomatoes is unproblematic. Once you got themmout of the refrigeratorkl you can prioecess the paste in any way you want. You will just get a more intense separation of paste and water, which can be countered in following processing.