Indexing Strategy for the query performance

I have a question on indexing strategy as i am trying to do indexing for a database. I understand the basic indexing strategy which are: - Clustered index on PrimaryKey - Add Non Clustered index for other columns as per requirement. - Should have indexes for WHERE/JOIN/GROUP BY/ORDER BY columns - Covering indexes for columns to avoid keylookup. - Check the workload and avoid adding too many indexes - Index Foreign Keys - Index any other unique keys etc.. I still have some questions and i couldn't find an exact answer to my questions. Here is an example of a table that i have. USE [DEMODB] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Employee_Header]( [Id] [uniqueidentifier] NOT NULL, [PageId] [uniqueidentifier] NOT NULL, [Dept] [varchar](256) NULL, [DeptName] [varchar](256) NULL, [SubUnit] [varchar](256) NULL, [ShiftType] [varchar](256) NULL, [ReportDate] [varchar](256) NULL, [ReportTime] [varchar](256) NULL, [AccessNumber] [varchar](256) NULL, [AccessOnAfterDate] [varchar](256) NULL, [AccessOnAfterTime] [varchar](256) NULL, [EmpBand] [varchar](256) NULL, [WorkSite] [varchar](256) NULL, [Location] [varchar](256) NULL, [Location_FieldValue] [varchar](256) NULL, [Location_Description] [varchar](256) NULL, CONSTRAINT [PK_Employee_Header] PRIMARY KEY CLUSTERED ( [Id] ASC )WITH (PAD_INDEX = ON, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 80) ON [PRIMARY] ) ON [PRIMARY] GO As you can see [Id] is the primary key here.[PageID] is the foreign key and it is not unique. There are few queries which uses whereclause on `[Dept],[SubUnit], [ShiftType] and [ReportDate]'. One query displays columns [Dept] and [ShiftType] and other query displays [Dept],[ReportDate],[ReportTime],[EmpBand] 1. I am confused as to how to create NonClustered indexes with Include columns so that same indexes can be used to both queries Or 2. should i create separate clustered indexes for where each columns 3. then create a separate single NonClustered index with PrimaryKey column as unique column and all the display columns in the include section. 4. Should i just keep the display columns in the keycolumn section? Most of the examples available shows querying to a single table with an Id and one or more select column. Can someone help me to understand how you approach similar situations? I created two indexes as shown below. First one is for the where clauses.I have all the where clause fields added as key columns in this non clustered index `CREATE NONCLUSTERED INDEX [ix_Employee_Filters] ON [dbo].[Employee_Header] ( [Dept] ASC, [SubUnit] ASC, [ShiftType] ASC, [ReportDate] ASC, )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO` The second one is for the select columns.Some of the select columns are already part of the first index so i have only two columns that needs to be covered. So i added them as Include fields with Id(Primary key field) as the key column. `CREATE NONCLUSTERED INDEX [ix_Employee_Include_Fields] ON [dbo].[Employee_Header] ( [Id] ASC ) INCLUDE ( [ReportTime], [EmpBand]) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO` Still when i run and see the execution plan, i get the message that there is a missing index. `CREATE NONCLUSTERED INDEX [] ON [dbo].[Employee_Header] ([ReportDate]) INCLUDE ([Id],[Dept],[ShiftType],[ReportTime],[EmpBand])` I don't understand why query optimizer is suggesting to a date filed as key field and other fields in the include section. I already have a Nonclustered index with ReportDate among other where fields. Appreciate for sharing your approach.But can anyone answer/share your perspective on the specific example mentioned?