Even while being frugal, you can look great.
The three Fs of looking good are: fitness, fitment, fashion.
Fitness: You must be fit and healthy. An obese person, or a person with bad skin or hair or teeth, must fix those issues to the extent possible.
Fitment: You must choose and wear clothes which fit your body shape. Neither too big, nor too tight.
Fashion: You must understand certain principles of aesthetics. Read fashion magazines and observe well-dressed men on the internet. There are many, many sites (including GQ, The Sartorialist, /r/malefashionadvice), and though most of them are focused on western wear, you will gain a keen sense of color and style from them.
We have already covered fitness in terms of physical agility and strength.
Fitment is easy to understand but hard to achieve. /r/malefashionadvice is a good place to understand it. If you are not able to find clothes which fit well, tailors in India are inexpensive and if given the right instructions, will alter your clothes just right for you. It is better to have a few well-fitting clothes than many ill-fitting ones.
Now we come to the hardest part: style.
The first prerequisite to being stylish is that you need to care about your appearance. Religious philosophies which devalue aesthetics or good looks must be discarded. You should strive to look good because you can, and it is an addition to the beauty of the world. You are paying homage to nature, the universe and your humanity by looking the best that you can.
The second is that you should develop a sense of which styles looks good on you and which don’t, and what you are comfortable with.
The third is that you must choose quality over quantity: have a few clothes which look great on you, rather than a multitude of rags which you are loath to wear. There are many brands which charge a premium without having any extra quality, but there are many brands which genuinely have better fabrics, fit, color patterns, and longevity. If in doubt, choose the better brand.
You should critically examine your wardrobe and rebuild it slowly, perhaps over many months or a year or more. Choose your accessories carefully. Wear a wrist watch. Ditch backpacks and invest in shoulder bags. Get oxford leather shoes and matching belts. Buy white shirts and dark jeans. Get a blazer and a leather jacket. None of these costs a ton, but you need to invest time and effort in choosing the right thing.
To look good is to enhance your value in a very visible way. It is worth it!