Again,your shop is the first thing to start with in case you have one.it's just a bit simpler because since tips are voluntary you don't really need to chek the incoming payment and the exact amount.simply display the QR-code and check each day what came in.
With tips ,the nice thing is that you don't necessarily need to have a shop.ablog for instance or any other website is sufficient.you can display the QR-code or just your bitcoin address at the bottom of your page or wherever it seems convenient and let people decide how much they want to tip you.you can also view how this looks like in the footer of this German blog bitcoins21.
Another really cool way to get tipped online is changetip.this service allows you to integrate tips on all major social networks ,YouTube and gifthub.very nice!
Imagine you have a restaurant and want to encourage your customer to tip with bitcoins,there is this nice service :bctip is a website where you can print little paper voucher that have a certain bitcoin bialance on them.when your customer has one of these,he or she can simply give it to you on your employees and you can redeem it like coupon.