Tweak

Sharp Edges: Mark edges as sharp. Normals will be split along those edges.
Brush: This tool works similarly to a soft selection. Vertices closest to the center of the brush cursor move more than those at the outer edges. Use SHIFT to smooth vertices spacing.
– keep bounds while smoothing: With this option enabled, boundaries will be preserved while smoothing the mesh. Press SHIFT to smooth.
– through all groups: Operating Through All visible Groups.

Delete face/edge: Click (individually) or drag cursor along polygons to delete them. Hold the CTRL key to delete connected sets of polygons. Delete edges, edge rings, or edge loops.
Hold down CTRL key to quickly select & delete entire edge loops
Collapse: USE LMB on edge to collapse it. Use CTRL+LMB to collapse edge rings.
Split Rings: Split edge rings with a line.
Move: Tweak vertices, edges, and faces.
Slide Edges/Vertex: Use LMB to slide edges. CTRL+LMB will slide edge loops. Moving vertices along an edge. Pre-selection of edges is available.
Measure: Click to add points. Use SHIFT to align lines horizontally, vertically or diagonally. Press ESC to stop measure guide creation.

New click will start new guide. Click on lines and points to split lines or drag points. Measure guides may be used in other tools as visual markers or snapping guides.

Double click to erase point. Move nearby points together to erase captured point.
Use CTRL to avoid snapping to existing points or lines, for example when you need to start new line from existing point or line.

Show Open Edge: Open Edge of Mesh drawing by Red.