how very senior citizens can file their income tax return without physically going to the IT office ?

there are a very large no of income tax payers who prepare their returns all by themselves .The amount of tax is small or it may be even nil in some cases.If it is sent by registered post, the acknowledgement form is not received back.
If it is submitted electronically, there is the question of digital signature,( to subscribe to a digital signature is a costly proposition). In these days of electronics how it can be done in a proper way ?

The answer is to be on the Indian context

How are independent software consultants taxed on their income in India?

If I am an independent software consultant with variable incomes and variable+multiple expenses. How do file my incomes and how would I be taxed?
If I am an independent software consultant with variable incomes and variable+multiple expenses. How do file my incomes and how would I be taxed?

I would specifically like to know, what all categories are there under which I can show my expenses.
I want to evaluate 2 options in order to check which one would leave more money in my hands:

1] if working as a full time employee with ~33%TDS

OR

2] working as independent consultant with 10% TDS … and show the expenses individually.

Please guide.