Having toned arms isn't a masculine thing. Woman can be both strong and sexy. Strong arms are a beautiful thing because number one they are capable of being useful since they are now strong. And number two, you will look good in tank tops, sleeveless, strapless; basically anything that reveals your arms.
It's important when working out a muscle group, to try and work out using multiple movements to target every part of that muscle; top, bottom, and sides.
It's important to challenge your muscle as well, pick a weight that is neither too easy or too hard for you. Some struggle is key for growth. Always make rest days in between muscle groups too, to allow for recovery of the muscle.
Try to complete 10-12 repetitions of each movement. The goal is to complete 3 sets of each. I'm into get in and get out of the gym. So the least rest the better in between sets. This also helps keep your heart rate up and chances are you will get a better sweat in as well.
<3 Gi