1. Google Business Profile is the highest return
When somebody nearby searches for a hardware shop, cement dealer or tile showroom, what they see is a map with three listings. Being one of them is free and takes an afternoon: claim the profile, get the category and hours right, add real photographs of the shop and the stock, and ask satisfied customers for reviews. For a local shop this is worth more than any other marketing available, and most shops in most towns have not done it properly.
2. The contractor network is your sales force
In the material trade the person who decides where material is bought is usually not the person paying for it. Contractors, masons, painters, electricians and plumbers direct their customers, and they choose based on stock availability, rate consistency and whether you make their life easy. Building relationships with twenty or thirty of them, and being reliable rather than cheapest, does more for turnover than any advertising.
3. WhatsApp, used properly
Every customer is already there, which is exactly why it is easy to misuse. Three things are worth sending unprompted: the bill at the time of sale, the receipt when a payment is taken, and a statement on the first of the month. A rate list to your regular buyers when the market moves is welcome. Anything more frequent and you become the contact people mute, which costs you the channel entirely.
4. Ask for referrals, specifically
A satisfied customer will recommend you if asked and usually will not if not. The ask has to be specific — not "tell your friends" but "if you know anyone starting construction, give them my number". Contractors respond to a different ask: a clear arrangement about what they get and reliable stock when they need it. Vague goodwill produces vague results.
5. Being findable and being reachable
A board that is readable from the road, a phone that is answered, a WhatsApp that gets a reply within an hour during working hours, and someone at the counter who knows the stock. These are not marketing in any modern sense and they are what most shops actually lose customers on. Before spending anything on promotion, be honest about whether a new customer arriving today would have a good experience.
6. Measure what brings people in
Ask new customers how they found you and write the answer down for a month. Most shops discover the mix is nothing like what they assumed — usually far more referral and far less signage than expected. That one month of note-taking will tell you where to put your effort more reliably than any general advice, including this.