I may well eat my words after my twins are born but I'm a firm believer in the not letting the babies take over your life approach. With my older two I generally avoided mother and baby groups but that was because I found the other mums were generally very cliquey and competitive and eager to make themselves feel better by putting someone else down which is horrible.
I made friends with the other outcasts from the baby groups and we've been close friends now for 4 years and have all had second children (I'm the first to attempt a third and will end up with 4). We meet up en masse and so tend to take over wherever we go and this helps to shield you from worry when your babies cry. I think you need a group of supportive friends who have children too and who will all say nice things like "Don't worry, babies cry, everyone understands that it isn't anything bad you are doing" when the twins start wailing.
I don't think it is good to pander to a fuss at whatever age the child (or adult) is. This goes for grown ups who moan about a baby crying too. Only worry if their fuss is reasonable because you are in an exclusively adult place and are not doing anything about the crying. In parks and other childrens places, your children can have free rein to behave like kids, in-between places like coffee shops the children need to learn to behave well but you shouldn't stop going there if they don't, adult places like theatres or churches then you should just avoid or take the children out if they make a fuss.
My little girl has massive tantrums occasionally (perfectly normal at 2) - normally at very difficult times and my little boy was a very strong willed baby. Yes, people are bothered by it, yes, they do look at you like your children are the worst behaved they have ever seen and you are a terrible mother but you have to get this in perspective. The best behaved most wonderful children and babies will still do the naughtiest thing occasionally. Normally in public and at the worst possible time. It is very normal - no-one can be perfect all the time. I've found the more you get upset and worried about it happening the more likely they are to deliberately make a fuss and be naughty just to get at you or get themselves out of a boring situation.
In short just carry on with confidence doing whatever it is you've decided to do and try not to worry otherwise you'll be a prisoner in your own home. If you are on your own during the day the only way you'll be able to cope without help is through practice, the first few times you go out you just have to carry on with what you're doing despite a crying baby or two (eek) so choose places it doesn't matter like the park. The park is a place for children. If other adults can't tolerate normal children's behaviour then they are the ones in the wrong. If one or both start up you don't make the trip last longer as a punishment, you don't cut it short, you do try some gentle soothing and reassurance but you don't get upset and/or angry or desperate in trying to calm the baby and it doesn't affect the outcome of the trip - you go for the amount of time you planned or until you've done what you came for. Don't feel bad for taking two seconds to calm yourself while the baby is crying - it helps to give you perspective and analyse whether the cry actually needs something doing about it or not.
Providing the baby is not crying for something like food or milk or to get out of the pram (a reasonable request that you can do something about) and she's just cottoned on that if she cries she gets out of a boring situation then this will gradually work. When it does work make sure you praise the baby. Only allow her positive attention and make sure you give it every time it is deserved even if you are fuming because she has been crying constantly for the last 4 hours.
It is the same at night time - this can be a good time to practice helping the baby to deal with boredom. If you know the baby is capable of sleeping for x amount of time, you know she's not hungry or wet and she's warm and comfortable and you suspect she just wants attention then just ignore the crying. I always think pandering to it would be like if you woke randomly in the night to someone giving you £1million you'd make sure you woke at the same time the next night just to see if it happened again. If you got the reward everytime you'd be a bit put out if it suddenly stopped. This is what it is like with some babies. My little boy was (and is one) where bedtime is concerned - any excuse to be out of that bed! As they get older you can help them to make the link between the behaviour and it's negative consequences e.g. getting up at night leads to falling asleep in the day and missing something they want to do.
I had more of a problem with my little girl when we were in public. With her the main thing is preventing her temper from getting out of control in the first place. This, I normally do, by making sure she's not tired before we go out, by explaining what we're going to do before we do it and then massaging her ego a bit by telling her what a good girl she is and so she gets to come with mummy to do this big girl's thing. I realise a 6 month old can't understand that properly but I do think they pick up on your feelings so if you make sure she sees you are being nice to her and expecting her to be good she'll be more likely to be calm than if she sees you worrying about her crying and try to give her lots of attention while she's not crying.
Well, I hope all that makes sense! Lol