The total number of shards in a YugabyteDB cluster can be controlled through various methods, including the use of flags such as ysql_num_tablets and ysql_num_shards_per_tserver. The former controls the number of tablets per YSQL table, while the latter controls the number of tablets per tserver. The choice between these two methods depends on how much control is desired over the shard count. Additionally, YugabyteDB supports dynamic auto-splitting, which automatically handles shard splitting as data grows, and allows users to manually split existing tablets if needed. Indexes are also subject to sharding, with their own YCQL-specific syntax. Users can explore various resources on sharding, including blog posts, YouTube content, and community forums, to learn more about best practices for sharding in YugabyteDB.