You need info about different things before deciding on the indexes. Some of them are

Volume of data in the table (IMP),

Type of queries that are going to hit the table (IMP)

Purpose of the data , Connectivity , Concurrent connections, Server Hardware..... There are other considerations also but offhand i can think of these.

Of these the first two are most important and index design is influenced the most by them.

Clustered index keep the actual data in the leaf pages of the index in a sorted order. In many of the cases clustered index also functions as the Primary key/unique index and so you would want your most "selective" columns to be part of the clust index.