I believe what you primarily want to do with it, and how much you want to invest, should be the first consideration. Various tasks are more important than other components, so you can first choose the important element according to your budget, then choose the second most significant component according to the first component, and so on.
Only presume, for example, that you have a budget to create a decent PC that can run the latest games. If you have a 1920x1080 display resolution with a 60hz refresh rate there is a small improvement over a Gtx1060, or even a 1050ti. If you purchase a display, you could use an AMD Rx580 instead, as monitors supporting AMD's adaptive sync are less costly than those supporting a nvidia. The CPU is the next big element. Based on your graphics card, you can select i5 8400 as a decent amount of money is saved compared to i5 8600 K and i7, which are both less costly, when playing on the mid-level GPU. you have to save on your graphics card. You don't need a high-cost motherboard or aftermarket CPU cooler because you can't overclock an i5 8400. Expensive RAM modules look cool, but the cheapest modules from a well-known company would be workable without overclocking on the agenda. If you need it, RAM can be easily upgraded down the track. Finally, you may want to consider your graphics card's power and length specifications and select a case and power supply.
If you're instead making content and editing a video, it's mostly the CPU; so you might go to an i7 8700 with a cheaper graphics card, for example, in place of the i5 and GTX1060 combo.
It may not be your job to edit games or videos so you may not need a graphics card at all, you may be constructing a media pc or a home server with an i3 and a bunch of hard drives or an office PC without any extras.
1 TB of SSD sounds cool, but maybe you're able to get off with a 240 GB C drive instead of a cheaper mechanical HDD. You can easily format and reload the OS without losing any images, music , movies or whatever, by putting the C-driven drive on another disc or partition of your data.
I see people buying or designing computers sometimes and splashing out on an expensive motherboard and CPU thinking that they're going to make it quicker. But for general use, an expensive i7 would feel about the same on an expensive "gaming" motherboard as an i5 on a cheap motherboard. More expensive components give the average PC consumer little advantage after a certain point; my general rule is to figure out which components can make the most difference to you and design your PC around them, depending on what you are prepared to spend. In a modern PC, the CPU is not always the performance "bottleneck," and some individuals purchase more than they need.