This is probably the most common way people track their progress. Despite a lot people disliking scales, they do have their place in tracking progress. If your main goal is weight loss, you will probably want to weigh yourself to see how you're going!
To track accurately, I recommend weighing yourself everyday at the same time (in the morning after you've been to the toilet preferably). Weighing yourself everyday may seem crazy but the idea behind this is that you would record your weight and at the end of each week you would add them together and divide by 7 (or 5 if you were just weighing Monday to Friday) to get an average! Our bodies fluctuate in weight so much, so it's best to get a weekly average rather than relying on one days result. You may go up and down a couple of KG's each day, so by finding the average you'll be able to track your progress more accurately. Use notes in your phone or a memo book to keep a record of your weigh ins.
If you are using this method, be sure not to get hung up on what the scales say. If you are feeling better then you are making progress. The scales only show weight, they don't tell you if you've changed shape or gained muscle!
Here's an example of how you could do a record of your weight and find the average
Taking measurements is an awesome way to track your progress. If you don't have much weight to lose the scales can be disheartening as they aren't likely to change hugely. By taking measurements of various parts of your body you will be able to see whether or not your body is changing shape! This is also a good method if you're trying to work on a certain part of your body. For example many of us girls are trying to grow a booty! In this case, you may not be concerned with weight but more the strength and appearance of your glutes, so measuring would be a better method to track your progress. Here are some examples of parts of your body you can measure.
The main ones I would suggest doing would be upper arm, waist, hips and thighs, but you can do as many as you like! It is important to ensure you're taking the measurements from the same spot each time, so take note the first time you do it. Perhaps you measure a few inches up from your elbow to take your upper arm measurement or you might have a freckle you can use as a point of reference.
If you have a goal that isn't really appearance or weight driven, the above methods won't really mean much to you. Lots of people have strength goals or fitness goals, in which case you may need to take a more physical approach to tracking your progress.
If you are wanting to improve your overall fitness you may want to do something along the lines of timing yourself running a certain distance and writing down how long it takes each time you do it, that way you will be able to see if your time is improving and therefore your fitness.
If you don't go for regular runs you could do it a different way, for example you could create a circuit that you can do at home or at the gym. The first time you do this circuit note down how hard you found it and how you felt during and afterwards. A fortnight or a month later do that same circuit again and see how you felt this time compared to the first time you did it. Maybe you did the same weights but it felt easier or perhaps you felt you could do heavier weights. Maybe you jumped higher, ran faster, recovered quicker or felt mentally stronger. There are lots of ways you can improve!
If your goals are strength based it would be a good idea to keep a note in your phone or in a notebook recording what weights you do for each exercise. Next time you're doing that exercise you can check what weight you did last time and either do that weight again or move up to a heavier weight once you're ready. This is good to remind yourself what weight you're up to but also good for keeping you accountable. Some days you may feel unmotivated and want to pick up the lighter weights but if you can see in writing that you usually do the heavier one it will motivate you to push yourself!
You may want to write up goals as you go. If you're doing shoulder presses with 6kg dumbbells and you want to be able to do 10kg you could do something like this: