Ideally you will want to find time to practice your songs at home. If all did this then the repertoire would be learnt much more quickly and efficiently and more songs could be added. Of course the performance as a whole would be greatly enhanced and thus both audience and choir would get more satisfaction from a performance.
Just 20 min a day would make a big difference. It is easy to do and you don’t need to gather special equipment or dress for the occasion. The best way to ensure a regular practice session is to plan it in to your day and hopefully it will become natural that you will want to practice and improve.
Of course not all singers have time to do so and are part of a choir purely for the social side and that is fine too. It is a community choir after all with a lot of people with very different reasons for being there. Who knows that if some practice and thus sing better it might inspire others to improve too. Lead by example and some will follow.
If you have limited time then pick a phrase in a song that you find difficult. If you can play the piano then play the notes as you sing them. If you can’t then isolate the phrase on the practice track and play just that phrase a few times whilst singing along and watching the score. Try to work out exactly what it is you are struggling with. Just saying that something isn’t that good without analysing precisely what it was that you didn’t like isn’t very productive. Once you have decided upon what it is you don’t like you can use techniques listed earlier to improve. Focus on one at a time and repeat the phrase correctly a few times and then focus on a different issue.
Usually the point at which the difficulty manifests itself isn’t the problem but the notes just before. Fix that and the rest will be easier. It is important to notice small improvements and acknowledge them. Many of those will make for greater improvement in the long term. A lot of people are impatient and that hinders progress. Improving anything you like to do takes time and is well worth it in the end as things will become more natural and part of you.
Exercise
Is there time in your day to practice? When you practice conscientiously what do you notice?