No matter what instrument you are using to shave, make sure it is sharp. Sharpness means you will get a closer shave with less effort. It also means that you will do fewer passes and reduce the tugging of hairs. This, as already explained previously, can cause skin irritation after shaving.
So how often should you change the blade or razor of your choice? Following recommendations are based on average hair while shaving daily. If you happen to have extra coarse hair, you may need to change them more often. The opposite holds true if you have a very light beard or shave rarely. Best way to tell if your razor is dull is the feeling you get from it. If it’s tugging, cutting poorly and you get razor burn – it is time to change your razor.
But general recommendations are the following: Cartridge razors shouldn’t be used more than a month. Disposables last you around 5-7 days usually. Razor blade inside a safety razor usually 5-7 days. Electric shavers hold the edge longer, but then again you will never get the same closeness as with manual razors. For electric shavers, it is recommended to change the shaving head once a year.