Each bar in example 1 contains four repeated open string notes. Use your left hand to mute the strings from sounding when descending.
Example 2 changes between neighbouring strings. On the last beat of each bar rest your right hand playing finger to mute the string from sounding. Note that the right hand fingering changes when descending.
Example 3 changes strings on each note; notice when descending in bar 4 to 6 the picking finger does not change within each bar. Use your left hand to mute the strings on each rest.
Example 4 alternates between the low B string and all other strings.
Example 5 combines all strings randomly. Use right or left hand for muting on the rests.