How do the 4th, 5th,6th, and 8th amendment protect the rights of the accused?

4th- Protects from unreasonable searches of property without a warrant (self-explanatory why that protects accused)

5th- Right to remain silent (Basically) 
this means that if accused, you don't have to admit to anything. You can do the famous saying "I plead the 5th"

6th- Right to a speedy & Public Trial
This means that all persons accused of a crime have a right to go to court, have a fair trial, and be given a chance to prove innocence or plead guilty

8th- Protection against cruel and unusual punishment
This basically means the Judge cannot sentence someone to (let's say) 20 years in prison on a Jaywalking charge. This is just an example. Basically, it just states that punishments must suit the crime in order for it to be constitutional