Glides are sounds with a “y” between a consonant and a vowel. きゃ (kya) and じゃ (jya) are examples of these sounds. In Korean language, /za/ becomes /ja/ in certain conditions. Thus, Korean speakers sometimes have trouble pronuncing words like "おはようございます"and "ぜったい." (common mispronunciations are おはようごじゃいます and じぇったい, respectively)
Japanese children often have difficulty in pronouncing つ, they substitute ちゅ for it. This is a common developmental problem many Japanese go through. Thus, mispronunciation such as みっちゅ and ちゅくります below is regarded childish.
Tips for pronouncing glides and つ (tsu) words would be to sound out the consonant and slightly pull the tongue backwards for つ (tsu).
try my best/non-word