diff --git a/src/dvclive/live.py b/src/dvclive/live.py
index ce8d5357..48b5f94f 100644
--- a/src/dvclive/live.py
+++ b/src/dvclive/live.py
@@ -7,12 +7,14 @@
 import os
 import shutil
 import tempfile
-from pathlib import Path
-from typing import Any, Dict, List, Optional, Set, Union, TYPE_CHECKING
+from pathlib import Path, PurePath
+from typing import Any, Dict, List, Optional, Set, Tuple, Union, TYPE_CHECKING, Literal
 
 if TYPE_CHECKING:
     import numpy as np
     import pandas as pd
+    import matplotlib
+    import PIL
 
 from dvc.exceptions import DvcException
 from funcy import set_in
@@ -69,9 +71,9 @@ def __init__(
         self,
         dir: str = "dvclive",  # noqa: A002
         resume: bool = False,
-        report: Optional[str] = None,
+        report: Literal["md", "notebook", "html", None] = None,
         save_dvc_exp: bool = True,
-        dvcyaml: Union[str, bool] = "dvc.yaml",
+        dvcyaml: Optional[str] = "dvc.yaml",
         cache_images: bool = False,
         exp_name: Optional[str] = None,
         exp_message: Optional[str] = None,
@@ -379,11 +381,15 @@ def log_metric(
         self.summary = set_in(self.summary, metric.summary_keys, val)
         logger.debug(f"Logged {name}: {val}")
 
-    def log_image(self, name: str, val):
+    def log_image(
+        self,
+        name: str,
+        val: Union[np.ndarray, matplotlib.figure.Figure, PIL.Image, StrPath],
+    ):
         if not Image.could_log(val):
             raise InvalidDataTypeError(name, type(val))
 
-        if isinstance(val, (str, Path)):
+        if isinstance(val, (str, PurePath)):
             from PIL import Image as ImagePIL
 
             val = ImagePIL.open(val)
@@ -401,10 +407,10 @@ def log_image(self, name: str, val):
     def log_plot(
         self,
         name: str,
-        datapoints: pd.DataFrame | np.ndarray | List[Dict],
+        datapoints: Union[pd.DataFrame, np.ndarray, List[Dict]],
         x: str,
         y: str,
-        template: Optional[str] = None,
+        template: Optional[str] = "linear",
         title: Optional[str] = None,
         x_label: Optional[str] = None,
         y_label: Optional[str] = None,
@@ -434,7 +440,14 @@ def log_plot(
         plot.dump(datapoints)
         logger.debug(f"Logged {name}")
 
-    def log_sklearn_plot(self, kind, labels, predictions, name=None, **kwargs):
+    def log_sklearn_plot(
+        self,
+        kind: str,
+        labels: Union[List, np.ndarray],
+        predictions: Union[List, Tuple, np.ndarray],
+        name: Optional[str] = None,
+        **kwargs,
+    ):
         val = (labels, predictions)
 
         plot_config = {
@@ -491,7 +504,7 @@ def log_artifact(
         cache: bool = True,
     ):
         """Tracks a local file or directory with DVC"""
-        if not isinstance(path, (str, Path)):
+        if not isinstance(path, (str, PurePath)):
             raise InvalidDataTypeError(path, builtins.type(path))
 
         if self._dvc_repo is not None:
@@ -574,7 +587,7 @@ def make_dvcyaml(self):
         make_dvcyaml(self)
 
     @catch_and_warn(DvcException, logger)
-    def post_to_studio(self, event):
+    def post_to_studio(self, event: str):
         post_to_studio(self, event)
 
     def end(self):
diff --git a/src/dvclive/utils.py b/src/dvclive/utils.py
index a168de9e..8b762590 100644
--- a/src/dvclive/utils.py
+++ b/src/dvclive/utils.py
@@ -4,7 +4,7 @@
 import os
 import re
 import shutil
-from pathlib import Path
+from pathlib import Path, PurePath
 from platform import uname
 from typing import Union, List, Dict, TYPE_CHECKING
 import webbrowser
@@ -26,7 +26,7 @@
         np = None
 
 
-StrPath = Union[str, Path]
+StrPath = Union[str, PurePath]
 
 
 def run_once(f):