Working out without a defined plan or goal is a little like running a race without knowing where the finish line is. You could be putting in lots of effort, enough effort to actually win the race, but if you’re not heading in the right direction you’ll never see the true benefit of your effort.
This is why a specific goal is the most important step to take before you start a workout program.
A lesson can be learned from high performance athletes here. They do very specific workouts in order to maximize their performance in a very specific event. Sprinters do everything they can to sprint faster. High jumpers just want to jump higher, speed skaters want to be faster speed skaters. Powerlifters focus all their energy on getting better at 3 specific lifts (bench press, squat, deadlift). Olympic style weight lifters focus on the two olympic lifts (clean & jerk, and the snatch).
All of these examples are performance based, they have nothing to do with building a specific ‘look’ of their body. Bodybuilders, figure and fitness models all train for a specific look, shape, and leanness to their body.
The difference between training for a look vs a performance outcome is the specific workout routine you follow, how far you take it and what you want your body to look like at the end of the day. If you expect to be a world class speed skater or swimmer you’re body will take on the distinct look of these styles of athletes (based on the training that is required to get there). Same thing goes for every other performance based training goal.
If you want to look like a figure or fitness model then your training should be aimed at building that specific look.
Cross training and borrowing workouts from all different styles is fine for overall fitness/health. But if you have a specific body shape/look goal in mind the more specific you are with your workouts the faster you will get to your goal.
Being clear about your goal at the beginning is the first and most critical step to achieving that goal.