Make sure your workout shoes are comfortable. You're going to be pushing your body and the last thing you need is extra soreness or even an injury, because you didn't take the time to find shoes that fit properly. Your shoes don't have to be expensive, just make sure to walk around in them a bit, to make sure they fit your feet properly.
Investing into a set of free weights for your household can help you a lot. If you don't have time to go to the gym then you can work at the start or end of your day. Free weights around the household can also give you more motivation to workout to your true potential because you don't have a bunch of strangers staring at you.
While you work out your biceps, you should bend your wrists when you come up for each curl. By doing this, you force your biceps to work harder. This will, in effect, increase the net amount of muscle that you will gain and lead to a better workout.