On 5x5 i solve them either with making 3 1x1x2 blocks then making 1 1x1x3 and joining them. Or making 3 1x1x3 blocks and then joining them. but on 6x6 and 7x7 i just make the 1x1x4 and 1x1x5.
So you first make a 1x1x5 line connecting to the middle piece of the centre colour that you intend to make, you then expand that by making other 1x1x5 blocks, is that correct? It is not clear to me that you actually immediately put the 1x1x5 block into place after you have made it. If not, then that is one thing that you will need to improve on.
If it is correct, then that is a perfectly good way of approaching the centres (I do it in most cases). In which case my tips for you would be:
1) Follow a colour order every time you solve. For example, I always start with black (or white, depending on your stickers), and then do yellow second obviously (opposite centres first is generally recommended). After that I don't have a set colour, however I would recommend that while you are still learning you pick the next colour that you will do every time. This will spare you looking around trying to decide what to do next; you can prepare immediately for the third centre, and then obviously the 4th and 5th/6th.
2) Lookahead. Yes this is obvious advice. Are you following it though?
3) Turn as fast as you can. This might make it harder to lookahead, but at least if you are turning fast with gaps between moves it is better than turning slow with gaps between moves.
4) I'm not sure about the state of your cube, but I suggest more lube (if you are practising a decent amount then you should lube at least every second week). I found this is the best way to break in a v-cube to perfection.
Just as I was typing this I noticed that your location is "Australia". I know who you are so you have no excuses
. At the next competition in which we hold 7x7x7 you better be sub7!
good luck
and 5x5 4 mins
