It is a very rare moment, when somebody made a new JOSM tool, that must become one of main tools in you palette, like Building Tools or RelToolBox.

Meet Fillet Tools plugin. It will completely replace Fastdraw and partially replace Improve Way.

Silent let’s play demonstration on youtube: https://www.youtube.com/watch?v=agyY25jVeGM

OSM forum thread

Some important notes for newcomers of this tool:

1) Main buttons for this plugin: Shift-Enter-Alt.

• Enter = finalize drawing (press it instead of last click if you connect end of line to the other way).

• Shift + mouse roller = undo/redo drawed points

• Alt = disable way justification mode. (!)

2) Do not make self overlapping of drawed line. If you press Enter during drawed line overlapping - drawed line totally dissappears instead become new way object on the map. This dissappearing may cause big done work loosing. (!) If you made overlapping, unroll it back using Shift + mouse roller. Overlapped line is gray, not overlapped line is red.

3) If you start and finish new line on the other existing way, FilletTools works in “Part of way redraw mode” (existing lines justification mode). In this mode on pressing Enter all existing way part between start and finish points will be deleted and changed by new drawed line. To skip this mode (for example if you add new multipolygone to the existing one, like scrub to forest), you must press Alt button once at any time during drawing new line. (!)

4) Using mouse roller without pressing Shift zooms your map view. Also, during new line drawing anytime you can use “Download map data in current view” button, so you can draw this line even outside of downloaded area.