Hi Annabel, well done, it's clear to me that you are begining to grasp the concept of correcting a footpritn's position when mapping using imagery captured at an angle. There are a few inaccuracies in this changeset I have mapped these footprints as an example in https://osmcha.org/changesets/170626506. --- Before mapping take a moment to (litterally) note two fundamental properties of any imagery you're looking at;

1. The direction from which the scene is lit or shadows are cast.

2. The angle at which the imagery was taken i.e. which sides of buildings you can see. 

It appears to me that you did not account for the off-nadir imagery when buildings were close together and obscuring one another's walls. In cases like this either another imagery source which was captured from a different angle should be used, or adjecent groups of buildings where the base of at least one of them is visible should be selected (shift+LClick) before accounting for off-nadir and moved (m) in usison to position them more accurately (this works best if the height of the builings is similar). In OSMCha click the map icon and select ESRI which is closer to a vertical photo and see how some footprints are positioned well with respect to it while others are inaccurate. Please keep this feedback in mind when contributing in future. Thank you for your contribution. If you want to experience the OSM community or to get timely feedback from other mappers; I recommend that you attend a mapathon. You can find events here https://osmcal.org/