If you decide to put a portrait picture into your CV, remember: Smile and Shine; Wear something formal and simle, not a suit like you are going to join a carnival; Do not give employers a headache looking at emoticons you put in the photo background.
You do not want to look silly, don’t you? Neither does your CV! Do not spontanously make bold or italic text in your CV just because of your preferences. Only highlight the important headlines as Title, Company, Educational level, … to make them significant enough.
Font size does matter in your CV! Big fonts makes the employers feel like you are shouting and too small fonts makes their eyes tired. Make sure you choose the right font size (12 to 14 as a suggestion) and everything still looks clear when you print it out on a A4 paper.