Marco Corvi: topodroid has many features requested by users that probably use other programs than therion to draft their cave maps, anyways, i use therion for my cave maps, and here is what i do. (0) a note3 with a stylus: reasonable compromise between the size of the android and that of the caves (lucky surveyors might go for a 7" tablet) (1) enable only drawing tools that are supported by therion, otherwise i must go for metapost code (2) each topodroid survey can have many sketches, and i usually draw several sketches, except for very simple surveys. (3) switch off fractional 'extend" (4) switch off loop closure compensation: better see potential blunders (5) i usually use "normal" line style, and the decimation button to simplify them (if need arises) (6) pre-exporting: check every sketch with joining sketches using the sketch outline feature, and make then fit nicely (7) it may happen that a sketch needs to be splitted in two, but this is rare as i'm used to draw small sketches. i never user sketch merge (8) i use automatic station points, even if, unfortunately, topodroid puts in all the stations in the convex hull of the sketch, and there can happen spurious ones. i do not remember if midline hide helps for this, however, midline hide is something i use only when the midline is very messy, i usually go over the station points and remove those that do not belong to the piece of midline of the skatch: this is easily done with a "good" text editor (9) i usually do not use "line continuation", but i fix the gaps between wall lines with point line editings (snap to point and merge with line). i sometimes use the feature that shifts a portion of a line, but i find often easier to redraw the line and erase the old one. (10) i have the feeling that outline is no longer very important to therion (it is however for csurvey, but this is ot on this list), thus i do not pay much attention that wall lines are properly oriented. anyways when i notice a line should be reversed i do it, as it's quick (11) automatic export because it's a nuisance to export each sketch Evaristo Quidroga: First I have unified symbols in Topodroid and Therion, so that the symbols used in one are understood by the other. Both use semantic symbology, so the graphic symbol in each does not matter, only the attribute. Another important feature for me is to configure the Topodroid type of line: "SETTINGS/SKETCHING/LINES/Line Style: Bezier. When I make "sketch" on Topodroid I already think about Therion "scraps". I try to limit the length and prevent it from overlap itself, doing several or as much sketch as needed by survey trip. Every Topodroid Sketch is after a Therion Scrap. Topodroid export every sketch/scrap in one .th2 file. For me it is a bit annoying not being able to export several sketch/scraps in a single file, but I have learned to live with it and remedy it in Therion. After exporting to Therion the survey trip, I reorganize the data by survey or centerlines, in the cave .th file. I do all the editing processes in Therion (connect lines, check the sense of the walls, etc), since it is faster. I do the editing in each separate .th2 file generated by Topodroid. At this time I take the opportunity to rename the scraps according to the nomenclature adopted for the cave. Normally afterwards I group the scraps in files according to the levels or galleries of the cave. So it's much faster to make the joins. For this I copy with a text editor all the scrap commands from the individual file to the destination file. Then I open the destination file and move all the built-in scrap to its proper position. Another technique that I use sometimes surveying some gallery in several survey trips, is to continue with the same session, without creating a new session, but creating new sketches . So I can see the whole of the topography in the screen with the option overview. I just have to write down the date, team and start and end station, and then include it in the new centerline of the .th file. Well these some of my TOPODROID-THERION tricks that I now remember. Last month I gave a 3 days survey course: Digital Survey 3.0; where I explained all the workflow from the data collection with DistoX2, the data transfer and drawing with Topodroid, and making the final product in Therion.