diff --git a/src/commands/challenge.rs b/src/commands/challenge.rs
index 370ad11..945b075 100644
--- a/src/commands/challenge.rs
+++ b/src/commands/challenge.rs
@@ -41,7 +41,7 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
     match ctx {
         Context::Application(_) => ctx.defer_ephemeral().await?,
         Context::Prefix(ctx) => {
-            if ctx.msg.attachments.len() == 0 {
+            if ctx.msg.attachments.is_empty() {
                 ctx.msg
                     .reply(
                         &ctx.serenity_context.http,
@@ -99,7 +99,7 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
     let author = ctx.author();
     let mut submitted_images = Vec::new();
     for submission in submission_data.iter_mut() {
-        if is_matching_submission(&submission, author) {
+        if is_matching_submission(submission, author) {
             existing_submitter = true;
             let mut images: Vec<String> = submission["images"]
                 .as_array_mut()
@@ -137,7 +137,7 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
                     },
                     extension
                 );
-                images.push(file_name.clone().into());
+                images.push(file_name.clone());
                 let image = reqwest::get(&attachment.url).await?.bytes().await?;
                 let mut image_file =
                     File::create(format!("{}/{}", submission_images_dir, file_name))?;
@@ -185,7 +185,7 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
                 },
                 extension
             );
-            images.push(file_name.clone().into());
+            images.push(file_name.clone());
             let image = reqwest::get(&attachment.url).await?.bytes().await?;
             let mut image_file = File::create(format!("{}/{}", submission_images_dir, file_name))?;
             image_file.write_all(&image)?;
@@ -275,7 +275,7 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
                             e.description(description);
                             let mut embed_author = serenity::builder::CreateEmbedAuthor::default();
                             embed_author
-                                .icon_url(get_avatar(&author))
+                                .icon_url(get_avatar(author))
                                 .name(username)
                                 .url(format!("https://discord.com/users/{}", author.id));
                             e.set_author(embed_author);
@@ -311,7 +311,7 @@ pub async fn images(ctx: Context<'_>) -> Result<(), Error> {
     let images: Vec<String> = {
         let mut images = Vec::new();
         for submission in submission_data.iter() {
-            if is_matching_submission(&submission, &ctx.author()) {
+            if is_matching_submission(submission, ctx.author()) {
                 for image in submission["images"].as_array().unwrap().iter() {
                     images.push(String::from(image.as_str().unwrap()));
                 }
@@ -321,7 +321,7 @@ pub async fn images(ctx: Context<'_>) -> Result<(), Error> {
         images
     };
     let challenge_number = get_challenge_number();
-    if images.len() == 0 {
+    if images.is_empty() {
         ctx.say(format!(
             "You haven't submitted anything for Tegaki Tuesday #{}.",
             challenge_number
@@ -329,10 +329,10 @@ pub async fn images(ctx: Context<'_>) -> Result<(), Error> {
         .await?;
         return Ok(());
     }
-    let mut message = String::from(format!(
+    let mut message = format!(
         "Your submission images for Tegaki Tuesday #{}:\n",
         challenge_number
-    ));
+    );
     for (i, image) in images.iter().enumerate() {
         message.push_str(&format!(
             "（{}）<https://{domain}/{}/{}>\n",
@@ -368,7 +368,7 @@ pub async fn imagedelete(ctx: Context<'_>, number: i32) -> Result<(), Error> {
     let challenge_number = get_challenge_number();
     let mut submission_data = get_current_submission_data();
     for (i, submission) in submission_data.iter_mut().enumerate() {
-        if !is_matching_submission(&submission, &ctx.author()) {
+        if !is_matching_submission(submission, ctx.author()) {
             continue;
         }
         let mut images = submission["images"].as_array().unwrap().clone();
@@ -402,7 +402,7 @@ pub async fn imagedelete(ctx: Context<'_>, number: i32) -> Result<(), Error> {
             Err(ref e) if e.kind() == std::io::ErrorKind::NotFound => (),
             Err(_) => panic!("Failed to remove file"),
         };
-        let mut message = String::from(format!("Deleted **{}** from your submission.", image));
+        let mut message = format!("Deleted **{}** from your submission.", image);
         if images.len() == 1 {
             message.push_str(" As there are no more images left attached to your submission, it has been deleted.");
             submission_data.remove(i);
@@ -470,7 +470,7 @@ pub async fn suggest(
                 });
                 let mut embed_author = serenity::builder::CreateEmbedAuthor::default();
                 embed_author
-                    .icon_url(get_avatar(&author))
+                    .icon_url(get_avatar(author))
                     .name(username)
                     .url(format!("https://discord.com/users/{}", author.id));
                 e.set_author(embed_author);
diff --git a/src/commands/kanji.rs b/src/commands/kanji.rs
index 13ef69e..f57dd68 100644
--- a/src/commands/kanji.rs
+++ b/src/commands/kanji.rs
@@ -21,7 +21,7 @@ pub async fn i(
         }
         let kanji_info = get_kanji_info(character);
         covered_chars.push(character);
-        if kanji_info.len() == 0 {
+        if kanji_info.is_empty() {
             skipped_chars += 1;
             continue;
         }
@@ -34,7 +34,7 @@ pub async fn i(
     message = format!(
         "Found {} kanji{}\n{}",
         found_chars.len(),
-        if found_chars.len() == 0 { "." } else { ":" },
+        if found_chars.is_empty() { "." } else { ":" },
         message
     );
     if skipped_chars > 0 {
diff --git a/src/utils.rs b/src/utils.rs
index ef5f237..9961f32 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -332,11 +332,11 @@ pub async fn random_kanji(
                     .choose(&mut rand::thread_rng())
                     .unwrap();
                 let list = subcategories[subcategory_key].as_str().unwrap();
-                let kanji = random_from_string(&list);
+                let kanji = random_from_string(list);
                 display_kanji(ctx, kanji, &format!(", **{}**", subcategory_key)).await?;
             } else if subcategories.contains_key(&subcategory) {
                 let list = list[&subcategory].as_str().unwrap();
-                let kanji = random_from_string(&list);
+                let kanji = random_from_string(list);
                 display_kanji(ctx, kanji, "").await?;
             } else {
                 let message = format!(