There are two main components to getting your "beach body" ready. One is to strip away body fat, and the other is to make sure you have some muscle to actually show off. The best way to achieve both of these is to turn your strength training sessions into a cardiovascular workout as well. Circuit training is a great way to accomplish this. Choose 4 to 6 exercise, preferably compound exercises that hit multiple muscle groups and perform a set of each with minimal rest in between. Repeat the sequence of exercises 3 or 4 times, or test yourself to see how many rounds of the circuit you can complete in a given time.
By turning strength training into a cardio workout you'll not only melt away body fat, but also maintain the muscle that looks good on the beach. Marathon runners may be great endurance athletes, but no one gets jealous of how they look with their shirt off.
Try incorporating sprints into the end of a resistance training or cardio session. Sprinting after workouts will not only get your heart beating faster but it will also mobilize free fatty acids into the bloodstream that will be burning off for hours after exercising. Try hill sprints. Find a steep hill and sprint to the top, take your rest by jogging or walking down to the base and then sprint to the top again. Keep going until you are nice and sweaty and you will be sure to feel accomplished!
To get beach body ready, exercises that you can do are high intensity interval exercises with combination moves. High intensity intervals are giving it your all for a burst of time and then having a little recovery before you start the next exercise. Combinations moves are exercises working more than one body part at a time. An example of a combination move is a squat to a bicep curl and shoulder press. You are working multiple muscles, using your core to stabilize you, and moving at a faster pace to get your heart rate up!
Try a workout called Tabata, an effective type of interval workout that can be done in a minimal amount of time. Choose 4-6 exercises, body weight, plyometric and resistance band moves are best. The exercises will be done with a 20s:10s time ratio, meaning 20 seconds of the exercise hard, followed by a 10 second "rest" transition to the next exercise. So, start with the first exercise on your list and do it with 95% effort for 20 seconds. Wait 10 seconds only and begin the next exercise. Go through your list in this manner for 15-20 minutes. If you've done it correctly, you should be sweaty and tired at the end!