diff --git a/src/clipboard.cpp b/src/clipboard.cpp
index 8db3b9f..152ce3a 100644
--- a/src/clipboard.cpp
+++ b/src/clipboard.cpp
@@ -242,7 +242,7 @@ void GraphicsWindow::PasteClipboard(Vector trans, double theta, double scale) {
 void GraphicsWindow::MenuClipboard(Command id) {
     if(id != Command::DELETE && !SS.GW.LockedInWorkplane()) {
         Error("Cut, paste, and copy work only in a workplane.\n\n"
-              "Select one with Sketch -> In Workplane.");
+              "Activate one with Sketch -> In Workplane.");
         return;
     }
 
diff --git a/src/constraint.cpp b/src/constraint.cpp
index fb679df..d33e67b 100644
--- a/src/constraint.cpp
+++ b/src/constraint.cpp
@@ -422,7 +422,7 @@ void Constraint::MenuConstrain(Command id) {
                 // Horizontal / vertical symmetry, implicit symmetry plane
                 // normal to the workplane
                 if(c.workplane.v == Entity::FREE_IN_3D.v) {
-                    Error("Must be locked in to workplane when constraining "
+                    Error("A workplane must be active when constraining "
                           "symmetric without an explicit symmetry plane.");
                     return;
                 }
@@ -452,7 +452,8 @@ void Constraint::MenuConstrain(Command id) {
         case Command::HORIZONTAL: {
             hEntity ha, hb;
             if(c.workplane.v == Entity::FREE_IN_3D.v) {
-                Error("Select workplane before constraining horiz/vert.");
+                Error("Activate a workplane (with Sketch -> In Workplane) before "
+                      "applying a horizontal or vertical constraint.");
                 return;
             }
             if(gs.lineSegments == 1 && gs.n == 1) {
diff --git a/src/graphicswin.cpp b/src/graphicswin.cpp
index d8b1a1d..4878e60 100644
--- a/src/graphicswin.cpp
+++ b/src/graphicswin.cpp
@@ -902,8 +902,9 @@ void GraphicsWindow::MenuEdit(Command id) {
 
         case Command::SNAP_TO_GRID: {
             if(!SS.GW.LockedInWorkplane()) {
-                Error("No workplane is active. Select a workplane to define "
-                      "the plane for the snap grid.");
+                Error("No workplane is active. Activate a workplane "
+                      "(with Sketch -> In Workplane) to define the plane "
+                      "for the snap grid.");
                 break;
             }
             SS.GW.GroupSelection();
diff --git a/src/group.cpp b/src/group.cpp
index ae64acc..b1206e5 100644
--- a/src/group.cpp
+++ b/src/group.cpp
@@ -133,7 +133,7 @@ void Group::MenuGroup(Command id) {
 
         case Command::GROUP_EXTRUDE:
             if(!SS.GW.LockedInWorkplane()) {
-                Error("Select a workplane (Sketch -> In Workplane) before "
+                Error("Activate a workplane (Sketch -> In Workplane) before "
                       "extruding. The sketch will be extruded normal to the "
                       "workplane.");
                 return;
diff --git a/src/mouse.cpp b/src/mouse.cpp
index 58f1857..7b0ff4b 100644
--- a/src/mouse.cpp
+++ b/src/mouse.cpp
@@ -954,7 +954,8 @@ void GraphicsWindow::MouseLeftDown(double mx, double my) {
 
                 case Command::RECTANGLE: {
                     if(!SS.GW.LockedInWorkplane()) {
-                        Error("Can't draw rectangle in 3d; select a workplane first.");
+                        Error("Can't draw rectangle in 3d; first, activate a workplane "
+                              "with Sketch -> In Workplane.");
                         ClearSuper();
                         break;
                     }
@@ -1005,7 +1006,8 @@ void GraphicsWindow::MouseLeftDown(double mx, double my) {
 
                 case Command::ARC: {
                     if(!SS.GW.LockedInWorkplane()) {
-                        Error("Can't draw arc in 3d; select a workplane first.");
+                        Error("Can't draw arc in 3d; first, activate a workplane "
+                              "with Sketch -> In Workplane.");
                         ClearPending();
                         break;
                     }
@@ -1058,7 +1060,8 @@ void GraphicsWindow::MouseLeftDown(double mx, double my) {
 
                 case Command::TTF_TEXT: {
                     if(!SS.GW.LockedInWorkplane()) {
-                        Error("Can't draw text in 3d; select a workplane first.");
+                        Error("Can't draw text in 3d; first, activate a workplane "
+                              "with Sketch -> In Workplane.");
                         ClearSuper();
                         break;
                     }