Upvote:1
If you've been granted a UK visa before and your visit was entirely within the bounds of that visa, not even going so far as to stay the maximum allowed time*, then this will count for a lot of points towards being accepted again with little trouble.
Basically the immigration authorities want proof you'll behave and go home when you're meant to. Having already done this 2 out of 2 times is a good precedent.
*this does cause alarm bells. Staying a day short of 6 months on a 6 month visa, though technically legal, would put the immigration authorities on alert. In your case of staying just a month though it's a positive.