I would like to do intarsia knitting (I believe it is called intarsia) using two different colours one for the ribbing and the lateral sides (where are the buttons and button holes) of a child’s cardigan that opens in the front and one different colour for the inside., I experience problems when I try to go from one colour to the other. I know I have to cross the yarns but I have not done it satisfactorily yet. I am a novice knitter and I would really like to switch from one colour to the other and vice-versa without creating a hole in my sweater. I hope somebody will be able to explain to me very clearly what I should do. Thank you in advance.