When potting on here is how I always get the plant in the middle of the pot.  In the photo I am putting a 3" pot into a 4".  Enough compost is added  to the bottom of the 4" to bring the 3" up to the right level, place the smaller pot in the middle of the 4".  Fill the space in between with compost.

POTTING ON A 3" INTO A 4" POT.

Before removing the inner pot, tap all of it on the bench then top up with more compost.  The reason I do this is to make sure it does not all collapse on me when it is removed.

Remove the 3" pot from the plant then just drop it into the waiting space in the 4", tap on the bench to settle it in.  If need be add more compost to any space left in the top of the pot.  Repeat this every time that the plant is potted on until it reaches its final pot.

IMPERIAL BUTTERFLY

This is something I find useful when watering.
When checking the plants, all the ones that do not need water, I place a cane in the pot.  The next day all I have to do is check the ones with canes.  If they then want watering, I do so and then remove the cane. 

How I treat cuttings that are harder to root. 
This is what I do to some of the problem Angels.  I take a 2.5" pot, put some cutting mix in the bottom, then place a 1.5" pot in the middle and fill in around the sides with the mixture, firming as I go.  Any compost that gets in the middle pot is emptied out.  Place the cuttings in between the 2 pots, firming in around each one.  As you can see in the photo this works well as all are rooted.  I removed a cutting so the inner pot could be seen.
                                               BONSAI

WENSUM

Rather than throw these miniatures away as they had become woody, I thought I would try my hand at making them into Bonsai. The photos of Wensum & East Sussex were taken a day after they were potted up on 24.09.09, so I have my fingers crossed that they will be OK and make new roots.  As you can imagine I had to remove so much of the old root ball to get them into Bonsai pots.
Cardington was done at the same time, and has settled in and started to flower in July.

CARDINGTON IN FLOWER JULY 2010

EAST SUSSEX

Below is an old plant of Golden Petite Pierre that I have turned into a Bonsai.
I thought I would give it a go, as the flower heads are quite small on this variety.

GOLDEN PETITE PIERRE