"Cash or Credit Card?" - At the point of sale, ask your customer if they'd like to pay with their credit card. At this point - once their card is in your hand - you may want to have an upsell lined up to offer in addition to what they're going to be purchasing. Regardless, it's statistically proven that simply asking this question will increase the ease of spending into your business - driving up the frequency AND size of your orders...
Collect Receivables (Money Owed) - Any unpaid balances and accounts receivable that your business is still in waiting for (customers haven't paid yet) should be collected on as soon as possible. Now that you can accept credit cards, it's going to be a lot easier to collect from your customers - and all
North American Bancard Agent you'll likely need to do is inform them that there's an easy way to clear up an invoice just by paying with their card of choice. See this article for an example of how powerful and profitable this actually is...
Here's my challenge to you, in closing...
Implement even just one strategy (above) into your business operations this week, to see whether or not it will actually make a difference. When you take a look at your sales figures that week, there is a good chance that you may see a positive trend developing.