If you're a heavy producer of precum, keep this in mind: On occasions when you think it's likely that you're going to get sexually aroused, you can wear a condom. Preferably not an oversize one, or there's the risk that it might work its way off your non-erect tool. (Precum can ooze out without your having an erection.) This system works pretty well if you're not involved in a lot of action & moving about -- and if you wear briefs, which hold your penis in place. Slippage would be more likely with boxers, since they tend to let you hang. The lube fluid will collect in the rubber instead of soaking through your undershorts and your pants. It's a little inconvenient to have to take the condom off when you go to the bathroom, and then put it (or another one) back on -- but it's sure better than advertising to any and everyone around you that you're oozing sex fluid.
Of course, in some situations you might think it's just fine to "let it show." And that's OK too.