Well, just in the nick of time here it is...
Since becoming a stay at home mum going to the park has become one of our favourite, cheapest and easiest things to do. But it's also one thing where I've learnt to follow the boy scout motto and "be prepared".
1) Find a nice park - sounds simple but it really is better if the park is one you all like going to. We have two near-ish to us but we prefer 'the little park'. So called because it is the smaller of the two. It's a two minute drive and a 10/15/20/30 minute walk depending on the walkers willingness! There's a good range of equipment for all ages, a few benches (not enough though, and some picnic tables would be fab too - can you hear me city council?!) and it's all enclosed.
2) Bring snacks - first few times I made the mistake of not bringing snacks and had the mortification of my child hovering round the mum who did have snacks looking waif-like. Now I bring stuff for me, my kids and other random kids too. Sometimes before we go we walk to the local coffee shop and get me a big coffee (coffee cart would do a roaring business in the park) and then we are all happy! I've also administered emergency biscuits to injured children and it's a good way of helping break the ice with other parents.
Which brings me to
3) Talk to people - I've given up caring about looking like a loon. Most other parents there are happy to have a chat. As a naturally shy person I tend to be nervous of talking to people but it's easy to strike up a conversation 'how old are they?', 'lovely weather', or more likely 'terrible weather!'. It means the next time you go there may be a familiar face there and friendships bloom. Well, to be honest, I've not made true friends from going to the park but I have made people I can say hello and pass the time with.
4) Entertainment for you - this is where the iPhone comes into its own. If there's no one to talk to then you can look at the web, take photos, listen to the radio etc etc. I tried bringing a book, kindle and paper but it never really seemed to work; the need to occasionally check on the children meant I kept losing my place.
Other top tips? Be prepared for all weather I bring sunglasses and gloves with me, have rediscovered the joys of the body warmer (or gillet to my mum!) for layering up and find a big scarf to be useful for neck and knees!