Face shaving. Sos

i swear iv tried 5 3 and 2 blade razers. shaving cream a d soap. iv tried shaving before and after shower. before and after mousterizer. but my neck i cant get clean shaved. either theres stubble (not 5 oclock shadow) and on top red and bumpy. i need tips. i wanna go un oublic but thats the biggest clock factor atm. please help!