This may depend on the specific context and personal preference.
My experience regarding writing Blog articles comes mainly from a couple of fiction short stories, which is quite different from what you are doing. When writing fiction I write in English from the start because I don't intend do publish a German version of it. It's the same as with an answer here on StackExchange. There is no merit in writing a German answer if it's not for German.SE, so I feel like it would be a waste of my time.
If I were to write about a difficult topic, for example programming, on the other hand I would feel more at ease when writing in German. It's easier, I have to search for words less, which would take up precious time where I need to concentrate on the problem at hand. It would still feel like a waste of time if I never intent to publish the German version though, so it would be a case-by-case decision.
Your problem seems to be quite typical. Look for example at the question What language should I write my programming blog post in? for a slightly different take on the matter, as that user was asking about whether the final product should be published in one language or the other. Disclaimer: one of the answers is my own. In the comments I mentioned the possibility to create two articles - a more lengthy one in your native language and a shorter one in English. I can't remember even havin seen that and I wouldn't do it myself, but it's a possibility that you could think about.
All in all: if you feel that writing in English is easy and doesn't have a lot more complications then writing in Russian you should just write everything in English if you are not planning on publishing your Russian version, too - it will take less time in total. If, on the other hand, you feel that translating is easy, fast and doesn't need a whole lot of further rewriting (you should re-read and re-write translations, too, to be sure that they are as good as they can be), but writing in English distracts from the difficult topic you are writing about or you just can't seem to find the right words when you need them you should write in Russian first and then translate your article to English. The final decision is up to you.