The first thing that you need to do is to select the right handkerchief. You will find handkerchief of different designs and fabric available in the market. In order to buy the best handkerchief for your suit, try to remember the shirts that you would wear with your suits in the coming days. The pattern on the handkerchief should be the one that compliments the pattern on the shirts that you are going to be wearing with your suits. If you have a mix of shirts with stripes and plain shirts, then go for two handkerchiefs, one with stripes and the other one plain. When you wear your suit with a shirt with stripes, put the striped handkerchief in the breast pocket of your shirt and when you wear a plain shirt, accessorise your suit with a plain handkerchief.
Try to get the handkerchief in a colour that complements the colour of tie that you would be wearing with you. Since you will most likely have a variety of ties in your cupboard/drawer, you would need to have a variety of handkerchiefs as well, so that you can match them with the tie of the day. If the tie has a pattern on it, match the handkerchief with the primary colour of the tie.
Once you have the right handkerchief with you, make you get it pressed. Spread it out and iron out all the creases that are on the fabric so that it can be neatly folded later.
There are three kinds of folds, square fold, pointed fold and flair fold for a handkerchief. The first and second folds are commonly used when a suit is being worn to a business or professional event, while the third type of fold is typically chosen for a more casual event such as a wedding.