After doing some research, I have noticed I have been saying the word "to" as [tʃu:], while most dictionaries and sources say I should pronounce it as [tu:]. But I have the impression that "to" is not pronounced with a clear t, at least in the most common variants of English. This also seems to happen with other words beginning with "to", such as "tomorrow" and "today".
Is this pronunciation of "to", [tʃu:], valid?
Are there any variations regarding the "t" in this word (excluding the "quick" informal pronunciations, which I am aware of)?
I am not a native speaker.