Boris, there's a law of nature to the effect that all cheap tripods are, well, cheap. Flimsy. Unstable. It goes with the price.
How much money are you thinking of spending, how much can you afford to waste, and what (camera, longest lens) do you want to put on top of your tripod?
My first tripod was a Quickset Hobby. Cheap thing, not bad at all. I replaced it after it disappeared in transit.
I now have some decent, they say, metal tripods in the closet and a couple of wooden ones that I use. An all-metal Star-D imitation Tiltall that I retired when I needed a fluid head. I replaced it with a Bogen/Manfrotto 3221/055, retired after serious testing found that it was the reason I had difficulty getting really sharp shots with a Nikon hung on a 700 mm lens. The tripod's big weakness turned out to be torsional vibration. The platform vibrated in rotation if the legs were extended because the bearing sections between the legs were short and allowed the sections to move a little relative to each other even with the clamps as tight as possible.
All three of metal tripods I've had had tubular (circular cross-section) legs. I don't see why they should be less troublesome than tripods with square section legs.
I replaced the Bogen/Manfrotto with a Berlebach 8023 (wooden) that I got on sale. It has much much longer bearing surfaces between the leg sections than any of my metal tripods and is much stiffer in torsion. Its big weakness is the center post. Even clamped down as firmly as possible, it can rock a little relative to the platform. This is a problem only with my longest lens, a 900.
I still use the Berlebach, also use an ancient Ries Model C (wooden). The Berlebach is a good tripod, center post blues notwithstanding, and is much easier to set up. The Ries has no center post and so far I've had no problems at all with it. Setting its platform's height and leg spread isn't as easy as I'd like.