How can we prepare budgeting for the company?

Budgeting mainly depends upon Company's structure;

Whereas, I have come across with Construction Company Budgeting system under ERP SAP platform

We follow WBS (Work Budget Structure) system 

Eg. Starts with Income

Then

Direct Expenses (or) Major Project Procurement 

Define various Direct expenses here with as per Work Structure

Whereas, ABCD Project

ABCD-DE-1000

ABCD-DE-2000

(Here ABCD Name of Project, DE is Direct Expenses & 1000 is code assigned to identify particular Work Budget)

In-Direct Expenses

Define various In-Direct expenses here with as per Work Structure

Same manner

ABCD-IE-1000 Travelling

ABCD-IE-1001 Travelling/ Business Trip (Under Travelling)

ABCD-IE-1002 Travelling/ Hotel Expenses        -"-

ABCD-IE-1003 Travelling/ Air-Ticket                    -"-

ABCD-IE-2000 Welfare

................

................

ABCD-IE-3000 Stationery 

................

................

Contingencies

Miscellaneous

There're many ways to prepare Budgeting depending upon one's Company's policies, guidelines also, Job-Cost compatibility/structure of an Accounting Software on which you're working.

This is my effort to convey example on Budgeting structure, I don't advice you to follow the same format/ procedure.