Sometimes a new DE shaver will assemble the razor with the baseplate upside down, and then the razor won't cut.
Photo showing baseplate positions.
Also, I suggest that you read
this post on blades and get a blade sampler pack—5-6 different brands is ample.
Try 3-4 brands of blades (trying them in alphabetic order is as good a way as any) and then stick with the best of those for two months so you can master technique without being distracted by blade variability.
Following the two-months sticking with one brand, I suggest that you then try one blade of a new brand once a month. If the new brand is better, switch to that as your regular brand; if it's not, then stick with your old brand. Then a month later try a blade of another new brand and make the same decision. After a year, you might return to the early rejects: with improved technique, they may turn out to be good after all.
This method means that most of the time you shave with a brand that is good for you, and that you always are comparing just two brands at a time: your regular brand and the new brand you just tried. You can stop the exploration at any time. Most will at some point encounter a brand that takes their shave to a whole new level and thus lose interest in further exploration.
Since a brand (that's) best in one razor may not be best (or even good) in another, a certain degree of exploration—trying at least 3-4 brands—is recommended for any new razor. Since you now know what a really good blade feels like (from the old razor), you know what you're looking for in the new razor.
The most common problems novices encounter are:
- Using too much pressure against your face. Pressure should be very light, just enough to keep the razor's head in contact with your skin as you shave.
- Holding the razor at a bad angle: cartridge razors work best with the handle close to the face; with DE razors, the handle is held farther from the face. Move the handle away from your face until the cutting sound and feel stops; then move the handle closer until the cutting sound and feel resumes. The optimal angle is close to that: experiment judiciously while listening to the cutting sound (clearly audible in a silent bathroom).
- Poor prep: use true lather (made from a shaving soap or shaving cream using a shaving brush and water). Cartridge razors have a lubricating strip which helps with canned foam or gel, but DE razors don't have that.
- Ignoring the grain of the beard: use this interactive diagram to map the grain of your beard. By far the most popular shave pattern is the three-pass shave: with the grain (WTG), across the grain (XTG), and finally against the grain (ATG), after the stubble's been reduced. Lather before each pass and rinse after each pass. When you rinse after the first pass, you'll feel a fair amount of stubble remaining. This does not mean that you should use more pressure. DE shaving consists of progressive stubble reduction, and the next two passes will clean it up. (Avoid shaving ATG in areas in which you tend to get in-growns: for those areas, the third pass can be XTG in the opposite direction.
Muscle memory will interfere with intentions regarding angle (and pressure as well) so at first you have to pay close attention.
Hope this helps.