You should be able to clearly explain how it makes you feel. But be careful to not use words such as, "You do this" or "You make me feel," which will immediately put him on defense. Instead say, "I feel" or "It makes me feel."

Help Him Find Solutions

The idea isn't to open his eyes to a bad habit and then leave it at that. Be willing to help him find a solution.

Try to come up with realistic, helpful ideas. Telling someone to just stop doing something isn't a way to provide support and motivation. You should be willing to be part of the solution.

It could be that his bad habit is something he learned as a child. It may take a bit longer to overcome. Or it could be that his bad habit is simply a matter of changing one thing.

Also check out... Irritating Guy Habits Explained When it's OK to Reconcile with Your Ex Relationship Lies that are OK to Tell Signs Your Partner is Too Controlling

For instance, you may have started to feel more like a maid to your man. He drops his dirty clothes wherever he happens to be standing at the moment. It's a bad habit that you aren't willing to put up with.

A simple solution might be providing a basket or laundry hamper in the room he most often gets undressed. If he doesn't have the tools available to change his habit, don't expect much progress.