The best way to accomplish this is to make and KEEP him as sexually aroused as possible as much of the time as possible. So let's talk about things you can do to keep him that way. The following are some examples of things you can do to insure that he will be thinking about you and about that next ejaculation if and when you decide to give it to him. Some things might not apply if your guy is in chastity.
Before you send your guy off to work in the morning, put a note in his pocket, lunch bag, or brief case. Somewhere he will be sure to find it after he has left the house. The note could be anything from a simple romantic “I love you” note, or it could include instructions for one or more of the other activities I will mention. You might say something like, “I can't wait until you get home because I want to play with your cock.” Or it might say, “At lunch, I want you to go into the bathroom and masturbate for five minutes, but don't cum, I want to play with you later, and I'll take care of that part.”
Instead of a note, you might just send a text message to his cell phone, or call him if you like. Even if you use the note idea, it would be a good idea to call or text him several times during the day. Two or three text messages designed to arouse him will go a long way towards keeping his mind on you during the day. Try sending him to work with a small butt-plug (and some lubricant) and then call or text him when you want him to insert it. Make him put it in an hour or two before he comes home so you can check that he did as we was told.
You can also try sending him to work wearing a pair of silky panties under his clothes. If yours won't fit him, buy (or have him buy) a pair that does fit. You could even have him buy them on his lunch break and put them while still at work. Make him take Tiger Balm or Icy-Hot to work with him and then make him apply it to his cock, balls or anus at some point during the day. That should keep him thinking about you.
One last idea for the working man. Send him on an errand. Have him stop by your favorite adult toy store and buy something for you. If you really want to humiliate him, make him buy a blow-up doll with all the features (Greek, French, etc.). There are things you can make him do with it once he gets it home as well, but that's another blog altogether.
So what do you do when you are both at home? Well, if you have no kids, it's easy. Make him spend some time naked while you remain fully dressed. Don't let him spend that time in the bedroom, either. Make him vacuum the living room, or wash the dishes, fix you dinner or even serve you sexually while you relax and watch a movie. There is no limit to what you can do with him when you have no children around. But just because you do have them, doesn't mean that there is nothing you can do.
If you have kids around the house try whispering something sexy like, “I would love to suck your cock right now.” Especially if it really isn't feasible at the moment. Also, take every opportunity to fondle him through his clothing. It will turn him on and you can do it almost every time you pass each other.
Invite him into the bedroom and give him a quick blow-job. Don't let him cum, just get him hard and ready to cum, then tell him you will finish it later (or not). You can send him to the bathroom with orders to insert a plug or to get himself hard and wait for you. You can surely find a few minutes to sneak off from the kids long enough to tease him in some way. Use your imagination and see what you can come up with. All you are wanting to do is give him a few minutes of teasing. Nothing more.
If you use everything at your disposal, your man should never be a few seconds away from thinking about you and what you might have in store for him later. You know what turns him on, use it. Use his fantasies to get his imagination working overtime. It's really not that difficult if you put your mind to it. The hard part is remembering to keep at it! Don't let an opportunity to tease him slip by. The more you do this, the better you will get at doing it and it will soon become second nature.