The razor bumps typically are a result of shaving wrong. Shave with the grain. What's that mean? Run your hand along your head the direction that has less of a dragging feel is with the grain. While shaving against the grain will get you a closer shave, it's also more likely to cause nicks and cuts if your scalp isn't used to it yet.
That's good advice, but I think the biggest mistake guys make initially when shaving against the grain is pressing too hard down on the blade. It's a lot better to do quick, gentle sweeps with the razor against the grain than one hard pass that'll cause irritation and cuts.
When I'm in a rush, I use the Series 5 it is a little pricey at around $275.00 USD, but it shaves almost as close as my Mach 5.
have a new blade out designed for sensitive skin, the . I gave it a go and found it a way easier shave than with my normal . It's worth checking out.Also, shave in the shower so you can really soak your hair and use lots of lubrication. Id recommend not shaving every day either, I find it easier with a few days growth.